NEW DELHI — A briefcase bomb tore through a crowd of people waiting to enter a New Delhi courthouse, killing 11 people and wounding scores more Wednesday in the deadliest terrorist attack in India's capital in nearly three years.
An al-Qaida-linked group claimed responsibility, though government officials said it was too early to name a suspect. The attack outside the High Court came despite a high alert across the city and renewed doubts about India's ability to protect even its most important institutions despite overhauling security after the 2008 Mumbai siege.
"Have we become so vulnerable that terrorist groups can almost strike at will?" opposition lawmaker Arun Jaitley asked in Parliament.
The bomb left a deep crater on the road and shook the courthouse, sending lawyers and judges fleeing outside.
"There was smoke everywhere. People were running. People were shouting. There was blood everywhere. It was very, very scary," said lawyer Sangeeta Sondhi, who was parking her car near the gate when the bomb exploded.
The government rallied Indians to remain strong in the face of such attacks.
"We will never succumb to the pressure of terrorists," Prime Minister Manmohan Singh said during a visit to neighboring Bangladesh. "This is a long war in which all political parties and all the people of India will have to stand united so that this scourge of terrorism is crushed."
The bomb exploded about 10:14 a.m. near a line of more than 100 people waiting at a reception counter for passes to enter the court building to have their cases heard. The blast killed 11 people and wounded 76 others. Their identities were not available, but no judges were among the victims.
People ran to assist the injured, piling them into three-wheeled taxis to take them to the hospital. Ambulances and forensic teams rushed to the scene, along with sniffer dogs and a bomb disposal unit, apparently checking for any further explosives.
Renu Sehgal, a 42-year-old housewife with a case before the court, had just received her pass and was standing nearby with her uncle and mother while her husband parked their car when she heard the explosion.
"The sound was so huge and suddenly people started running," she said. "We were all in such a big panic. ... I'm lucky I survived."
The court building was evacuated after the attack.
The blast probe was quickly turned over to the National Investigation Agency, established after the Mumbai siege to investigate and prevent terror attacks.
Police were scouring the city for possible suspects, searching hotels, bus stands, railway stations and the airport, said top security official U.K. Bansal. All roads out of the city were under surveillance as well, he said.
Late Wednesday, police also released two sketches they said were based on descriptions given by eyewitnesses who claimed they had seen someone with a briefcase waiting in line outside the building.
"We are determined to track down the perpetrators of this horrific crime and bring them to justice," Home Minister Palaniappan Chidambaram told Parliament.
An email sent to several TV news channels claimed the bombing on behalf of Harkat-ul-Jihad-al-Islami, an extremist group said to be based in Pakistan. The group has been blamed for numerous terror strikes in India, and the U.S. State Department says it has deep ties to al-Qaida and some members have trained at al-Qaida camps.
The email demanded the immediate repeal of the death sentence handed to Afzal Guru, a Kashmiri man convicted in the 2001 attack on India's Parliament, and threatened to target other courts, including the Supreme Court.
"We cannot say anything about the email until we have investigated it thoroughly," NIA chief S.C. Sinha said. "At this point the investigation is fully open and it's not possible to name any group."
The court bombing was India's first major attack since a trio of blasts in Mumbai killed 26 people on July 13. Suspicion fell on the shadowy Indian Mujahedeen, though no one has been arrested.
The bomb struck the High Court, an appeals panel below India's Supreme Court, even though the capital is on high alert because Parliament is in session. A small explosion on May 25 in a court parking lot appeared to have been a failed car bomb.
After the 2008 Mumbai attacks, the government expanded police recruiting and training, set up the NIA and established commando bases across the country so forces could react swiftly.
Jaitley, in Parliament, said the court bombing raised "deep concern" about "the kind of institutions and systems we have to build to fight this menace."
But officials say the number of targets in a nation of 1.2 billion makes it impossible to provide full security.
Dharmendra Kumar, a senior police officer, told reporters the court building itself was strongly protected by police but the explosion hit a busy main road outside.
K.P.S. Gill, a former senior police official, said Kumar's comment showed the police had a "ridiculous mindset" and India needed to rethink its strategy on preventing terror.
"If the public collects there, then you must protect that area," Gill said.
The attack rekindled memories of the string of deadly bombings that rocked the country in 2008, including a series of coordinated bomb blasts in New Delhi on Sept. 13 that killed 21 people. Many of those attacks were blamed on militant groups composed of disaffected Muslims furious at perceived injustices at the hands of India's Hindu majority.
That violence mostly abated after the November 2008 siege of Mumbai, when 10 Pakistan-based militants terrorized India's commercial capital for 60 hours, killing 166 people.
However, smaller attacks recently have raised concerns violence was returning.
Last Sept. 19, two gunmen on a motorcycle shot and wounded two Taiwanese men outside a famous New Delhi mosque. A few minutes later, a bomb rigged to a nearby car malfunctioned. On Dec. 7, a bomb exploded in the city of Varanasi, killing a 2-year-old, and a few months later came the failed attack on the High Court in New Delhi.
A statement Wednesday from Pakistan's government expressed "deepest sympathies" for the families of those killed in the explosion and the government and people of India.
The U.S. State Department also condemned the attack, offered condolences to the families and U.S. offered assistance to the investigation.
The U.N. Security Council on Wednesday "condemned in the strongest terms the terrorist attack" in New Delhi and expressed condolences, as did U.N. Secretary-General Ban Ki-moon.
The council said "any acts of terrorism are criminal and unjustifiable regardless of their motivation, wherever, whenever and by whomsoever committed."