(Edits)
* Tens of thousands of people protested in Homs as monitorstoured
* Residents urged Arab observers to see signs of "slaughter"
* United States condemns "escalation of violence"
* Sudanese head of monitoring mission says Homs "reassuring"
By Erika Solomon and Mariam Karouny
BEIRUT, Dec 28 (Reuters) - Arab League monitors aimingto verify whether Syria is ending a military crackdown onprotesters said they saw "nothing frightening" in an initialvisit to the protest hotbed of Homs although a longinvestigation would be needed.
Given the brief and limited nature of the monitors' tour onTuesday, the comments by the chief monitor could heighten theconcern of opposition activists that the observer mission couldbe used as a cloak of respectability by Damascus, issuingassessments whitewashing President Bashar al-Assad's record.
The Syrian Observatory for Human Rights, a British-basedactivist group, said security forces killed 15 people across thecountry on Tuesday, six of them in Homs, coinciding with themonitors' visit. Activists said 34 had been killed on Monday.
"Some places looked a bit of a mess but there was nothingfrightening," Sudanese General Mustafa Dabi, the chief of themonitoring contingent, told Reuters by telephone from Damascus.
"The situation seemed reassuring so far," he said onWednesday after his team's short visit to the city of onemillion people, Syria's third largest and epicentre of ninemonths of anti-Assad unrest.
"Yesterday was quiet and there were no clashes. We did notsee tanks but we did see some armoured vehicles. But rememberthis was only the first day and it will need investigation. Wehave 20 people who will be there for a long time."
Activists say about a third of the estimated 5,000 peoplekilled in unrest in Syria since the crackdown began in Marchdied at the hands of security forces in Homs. Dozens have beenreported killed in the past week.
The first group of monitors including Dabi were escorted bySyrian authorities into Homs on Tuesday and shown destruction inthe restive district of Baba Amr, where Syrian tanks were filmedfiring into residential areas the day before, according toamateur video recorded by activists.
Video reports, which cannot be independently verified, haveshown parts of Homs looking like a war zone. Constant machinegunand sniper fire is audible and corpses are mangled by blasts.Tanks have been filmed shelling anti-Assad targets in Baba Amr.
DARFUR RECORD
The Arab League says Dabi brings vital military anddiplomatic expertise to its unprecedented intervention in theinternal crisis of a member state.
But international human rights activists critical ofKhartoum say it is all but impossible to imagine a Sudanesegeneral involved in the Darfur conflict ever recommending strongoutside intervention, much less an international tribunal, torespond to human rights abuses in a fellow Arab country.
Dabi has held senior Sudanese military and government posts,including in the Darfur region where, the prosecutor of theInternational Criminal Court says, Sudan's army committed warcrimes and the United Nations says 300,000 people may have died.
WASHINGTON CONDEMNS "INDISCRIMINATE FIRE"
"We have seen horrific pictures of indiscriminate fire,including by heavy tank guns, and heard reports of dozens ofdeaths, thousands of arrests, as well as beatings of peacefulprotesters," Toner said.
"The monitors should have unfettered access to protestersand to areas most severely affected by the regime'scrackdown. They bear a heavy responsibility in trying to protectSyrian civilians from the depredations of a murderous regime.
PROTEST RALLIES
Emboldened by the monitors' first visit, about 70,000 Homsprotesters marched towards the city centre on Tuesday wheresecurity forces fired shots and teargas at them, activists said.
The military withdrew some tanks shortly before the monitorsarrived, in what the activists called a ploy to persuade themonitors that the city was calm. Video on the Internet showedmonitors confronted by residents imploring them to venturefurther into Baba Amr as gunfire crackled around them.
Some fearful residents shouted "We want internationalprotection" at the monitors in a video posted on YouTube.
The monitors were due to make a second tour of Homs onWednesday. Crowds have pleaded for them to get a thorough lookat the most violent neighbourhoods. Tens of thousands ofprotesters gathered on Tuesday in the Khalidiya district - oneof those yet to be visited by monitors.
One activist held up a sign that read: "We are afraid(that)when the monitors leave, they will kill and bury us."
The observers' visit is the first international interventionon the ground in Syria since the uprising began and protestershope what they witness will prompt world powers to take moredecisive action against Assad.
The Syrian leader says he is fighting an insurgency by armedterrorists, and that most of the violence has been aimed at thesecurity forces who have lost some 2,000 men.
International journalists are mostly barred from Syria,making it difficult to confirm accounts from conflict zones.
Activist reports just before the monitors arrived on Tuesdaysaid up to a dozen tanks were seen leaving Baba Amr and otherswere being hidden to fashion an impression of relative normalityin the city while observers were around.
Armed insurgency is eclipsing civilian protest in Syria.Many fear a slide to sectarian war between the Sunni Muslimmajority, the driving force of the protest movement, andminorities that have mostly stayed loyal to the government,particularly the Alawite sect to which Assad belongs.
Analysts say the Arab League is anxious to avoid civil war.Western powers have shown no desire to intervene militarily in avolatile region of Middle East conflict. The U.N. SecurityCouncil is split, with Russia - a major arms supplier to Assad -and China opposed to any hint of military intervention.
Assad's opponents appear divided on aims and tactics. Hestill has strong support in important areas, including Damascusand the second city Aleppo, and maintains an anti-Israelalliance with Iran. (Additional reporting by Ayman Samir; Editing by Mark Heinrich)