After more than two years of brutal conflict, there is no end in sight for the bloody war between the regime of President Bashar Assad and opposition fighters.
The United Nations estimates that at least 70,000 people have lost their lives since the start of the conflict in March 2011. One million refugees have fled to neighboring countries. Syria's cities are left destroyed, its streets deserted. Homes have been reduced to rubble, schools turned to dust.
HuffPost World takes a look at some of the key events and major players in Syria over over the past 24 months.
Angered by the arrest and torture of teenage boys who had spray-painted anti-government slogans on a city wall, protesters took to the streets in Syria's southern city of Daraa in March 2011. Security forces responded brutally, firing live ammunition and tear gas at the crowds and killing several protesters.
Protests gradually spread to other cities and the regime, too, stepped up its response. Assad offered concessions, but maintained his innocence and claimed that foreign agents were to blame for the unrest. Unimpressed by the government's offer, protests intensified during the spring and summer of 2011, and so did the regime's harsh repression of the demonstrations.
The violence reached new heights toward the end of 2011 as the conflict militarized. A growing number of defectors -- loosely organized in the Free Syrian Army -- staged guerrilla attacks against Assad's troops. Bombs targeting security forces and regime functionaries killed dozens in Aleppo and the capital, Damascus, throughout the spring. A major bomb blast targeting a high-level security meeting in July 2012 killed the country's minister of defense and the president's brother-in-law.
GRUESOME KILLINGS, BRUTAL ASSAULTS, CITY WAR
In February 2012, regime forces launched a brutal assault on the rebel-held neighborhood of Baba Amr in the city of Homs. Bombs and rockets rained down on the city for weeks, killing hundreds of people -- many of them civilians. The regime eventually pushed out the fighters, and the strategic victory was followed by attacks on the rebel strongholds of Idlib and Daraa.
Having significantly grown in numbers, rebels opened two new fronts in the fall of 2012, trying to capture neighborhoods in Damascus and Syria's largest city of Aleppo. As violence spread across the country, however, living conditions became increasingly dire. Food and fuel are scarce and bread lines often run for hours. Many hospitals have been destroyed and medicine supplies are at an all-time low. Air strikes and artillery have turned streets into impassable debris, schools have been leveled. Fearing returning airstrikes, some civilians have been forced to take shelter in caves and ancient tombs.
Reports of mass killings by government troops and pro-militiamen began to surface in 2012, around one year into the conflict. Ninety-two people, including more than 30 children, were killed in the town of Houla in the Homs province on May 25. At least 78 were murdered in the hamlet of al Qubair on June 6. Three weeks later, more than 200 people were reportedly slaughtered in the village of Tremseh near Hama. In the winter of 2012, dozens of bodies with gunshot wounds in the head washed up in a river in Aleppo.
However, opposition forces, too, have been accused of perpetrating crimes against government allies. "There may not be anybody with entirely clean hands," Suzanne Nossel, head of Amnesty International, told the Associated Press in November 2012 after a video surfaced that appeared to show Syrian rebels kicking and executing a group of captured soldiers.
More than a million Syrians have left the country since the start of the conflict, and hundreds of thousands have poured into refugee camps in neighboring Iraq, Jordan, Turkey and Lebanon. "When you stand at the border crossing, you see this human river flowing in, day and night," Panos Moumtzis, the UNHCR regional coordinator for Syrian refugees, told The Associated Press in March 2013. The exodus constitutes one of the worst refugee crises in recent history.
While the international community has been harsh on the Syrian regime, urging the embattled Assad to step down, world powers have shown unwillingness to interfere in the Syrian quagmire. European nations and the U.S. have provided humanitarian aid and promised the opposition non-lethal support, but have refused to go as far as to arm the rebels or impose a no-fly zone. Rumors of U.S. trainers aiding Syrian rebels in Jordan persist, however, and France and Britain are mulling whether to supply the rebels with weapons.
Repeated international initiatives to end the bloodshed and force Assad to step down have failed, largely because of Russia's continuing support for the dictator. Russia and China have blocked all significant action through the U.N. Security Council. The brief presence of Arab League and U.N. monitors in Syria also did little to prevent violence.
The international community and many inside Syria have become increasingly concerned about the presence of radical foreign militants fighting alongside the rebels. The militants, some of who previously fought in Chechnya and Iraq, aim to create an Islamist society in post-Assad Syria. However, the fighters have proven invaluable in battle and have been responsible for some of the most daring attacks.
The foreigners' presence also raises concerns over renewed sectarian tension in Syria. The majority of Syrians belong to the Sunni Muslim community, but the country also has significant Christian, Shia and Alawite groups. Assad belongs to the Alawite community, a sect that split from Shia Islam and makes up about 12 percent of the population in Syria. Alawites hold many key positions in the Syrian government and the Alawite Assad family has ruled Syria in the past decades by drawing upon the different minority communities, while most members of the opposition today come from the Sunni majority. The radical fighters, too, are believed to belong to the Sunni branch of Islam and are known to carry strong animosity towards the Shia and Alawite branches.
Activists and citizen journalists have distributed hundreds of photos and videos online that often show dead or injured children and civilians, mutilated bodies or destroyed neighborhoods. Yet verifying the content of these reports has proven nearly impossible. Media access has been severely limited in Syria, foreign journalists have been targeted by the regime and opposition fighters alike, Internet access is restricted and local journalists have been suppressed as the opposition and regime present competing narratives of the state of the country. Both Syrian and Western journalists have also been killed in the continuing conflict.
"Plenty of information is coming out from Syria, but the difficulty we find is in verifying the information," Soazig Dollet, head of the Middle East and North Africa desk of Reporters Without Borders, told Al Akhbar, a Lebanese newspaper. "Because of the state’s strict control of traditional media in the country, social media has become our main source of information. However, the question of who is sending out this information remains unanswered," he explained pointedly.
PHOTOS: TWO YEARS OF WAR IN SYRIA
March 2011: 120
Thousands of Syrians rally to show their support for President Bashar al-Assad, who is facing unprecedented domestic pressure amid a wave of dissent, in Damascus on March 29 2011. (ANWAR AMRO/AFP/Getty Images)
April 2011: 820
A protestor burns a portrait of Syrian President Bashar al-Assad during a demonstration after Friday prayers on April 29 2011 in Istanbul against the regime of al-Assad and the deadly crackdown on opposition protests. (BULENT KILIC/AFP/Getty Images)
May 2011: 850
A veiled woman takes part in a protest calling on Syria's President Bashar Assad to step down, in front of the United Nations headquarters in Amman, on May 21 2011. (KHALIL MAZRAAWI/AFP/Getty Images)
June 2011: 1,000
Syrian refugees arrive to a makeshift camp in the northern city of Idlib, in Syria, on June 13 2011. (MUSTAFA OZER/AFP/Getty Images) <em><strong>CORRECTION:</strong> An earlier version of this caption placed the city of Idlib in Turkey. Idlib is in Syria. </em>
July 2011: 1,600
Thousands of pro-regime Syrians wave their national flag and portraits of President Bashar al-Assad during a rally in Damascus on July 17 2011. (LOUAI BESHARA/AFP/Getty Images)
August 2011: More than 2,000
People hold pictures of Syrian president Bashar al-Assad and fallen Libyan strongman Muammar Gaddafi as they take part in a demonstration gathering activists opposed to Syria's regime of President Bashar al-Assad on August 28 2011 at Taksim Square in Istanbul. (BULENT KILIC/AFP/Getty Images)
September 2011: 2,700
A national flag hangs on a statue of Syria's late president Hafez al-Assad at the entrance of the flashpoint city of Homs on August 30 2011, as rights activists reported widespread anti-regime protests across Syria on the first day of the feast marking the end of Ramadan. (JOSEPH EID/AFP/Getty Images)
October 2011: 3,000
Supporters of Syrian President Bashar al-Assad wave Syrian flags during a pro-regime rally in Damascus on October 12, 2011. Assad's regime is facing international pressure amid a violent crackdown on anti-government protests that broke out in March across Syria. (LOUAI BESHARA/AFP/Getty Images)
November 2011: More than 4,000
Syrian soldiers carry on November 26, 2011 the coffin of a comrade reportedly killed in an ambush by an armed group in the flashpoint Syrian city of Homs. (AFP/Getty Images)
December 2011: More than 5,000
Free Syrian Army captain identified as Ahmed al-Arabi sits in a safe house near Wadi Khaled on the Lebanese-Syrian border on December 30 2011. (Si Mitchell/AFP/Getty Images)
January 2012: 7,100
Free Syrian Army fighters take position in a house on the Lebanese-Syrian border prior to a nighttime operation on January 2 2012. (Si Mitchell/AFP/Getty Images)
February 2012: 7,500
A Turkish journalist in Ankara, holds pictures of two journalists, French photojournalist Remi Ochlik and Sunday Times correspondent Marie Colvin, killed in an alleged rocket attack by Syrian regime forces against a makeshift opposition media center in the besieged city of Homs in Syria on February 22 2012. (ADEM ALTAN/AFP/Getty Images)
March 2012: More than 8,000
A defected Syrian soldier, now a member of the Free Syrian Army, stands outside a mountain outpost near the village of Janudieh in the northern province of Idlib on March 20 2012. (STR/AFP/Getty Images)
April 2012: Close to 9,000
Syrians pray over the bodies of Syrian violence victims at a funeral in the northwestern town of Kafr Zeta on April 10, 2012. (AFP/Getty Images)
May 2012: More than 9,000
A general view shows the Syrian flag flying next to destruction in the Bab Amro neighbourhood of Homs on May 2 2012. (JOSEPH EID/AFP/GettyImages)
June 2012: 14,000
A Syrian man carries a wounded girl next to Red Crescent ambulances following an explosion that targeted a military bus near Qudssaya, a neighbourhood of the Syrian capital, on June 8, 2012. (AFP/GettyImages)
July 2012: 19,000
Members of Jihadist group Hamza Abdualmuttalib train near Aleppo on July 19, 2012. Rebels seized control of all of Syria's border crossings with Iraq on July 19. (BULENT KILIC/AFP/GettyImages)
August 2012: 23,000
A Syrian boy whose family has been displaced due to fighting between rebel fighterws and Syrian government forces is seen near the Syrian border with Turkey on August 25, 2012. (ARIS MESSINIS/AFP/GettyImages)
September 2012: 30,000
A Syrian man carrying grocery bags tries to dodge sniper fire as he runs through an alley near a checkpoint manned by the Free Syria Army in the northern city of Aleppo on September 14, 2012. (MARCO LONGARI/AFP/Getty Images)
October 2012: 36,000
A Syrian boy plays on a destroyed tank near the rubble of a mosque that was destroyed during fighting between Syrian rebels and regime forces in the northern city of Azaz on September 23, 2012. (MIGUEL MEDINA/AFP/GettyImages)
November 2012: 40,000
A walnut tree stripped of its branches stands in the rubble of the Kalat al-Numan citadel, originally built during the Roman era some 2000-years-ago, after allegedly being bombed several times by the Syrian air force on November 18, 2012, in Maaret Al-Numan in southern Idlib province. (John Cantlie/AFP/Getty Images)
December 2012: 60,000
Smoke rises in the Hanano and Bustan al-Basha districts in the northern city of Aleppo on December 1, 2012 as fighting continues through the night. (Javier Manzano/AFP/Getty Images)
January 2013: 65,000
A boy plays with a balloon in a Syrian refugees camp in Azaz, near the Turkish border, on January 10, 2013 after snow falls. (EDOUARD ELIAS/AFP/Getty Images)
February 2013: More than 70,000
Syrian Zakia Abdullah sits on the rubble of her house in the Tariq al-Bab district of the northern city of Aleppo on February 23, 2013. (Pablo Tosco/AFP/Getty Images)