An opposition leader declared Thursday that the bloody ambush of the Sri Lankan cricket team shows security in Pakistan has "collapsed," while a government official said authorities had identified the attackers.

The country's cricket chief, meanwhile, dismissed as "totally fabricated" claims by British referee Chris Broad that police abandoned him and other officials during Tuesday's attack.

Six police officers and a driver were killed and seven players, an umpire and an assistant coach were hurt in the ambush in Lahore, which occurred despite government pledges to give the convoy the same level of protection afforded a head of state in the country wracked by a virulent militancy.

"The security system in Pakistan under this regime has collapsed because this government is too busy doing other things, they are too busy in their quest for power," Mushahid Hussain, an opposition leader told a televised media conference. "They should be held responsible."

Click to view photos of the attack (Warning: graphic content).

The attack has prompted intelligence officials to caution local authorities to be on the lookout for possible similar assaults to American sporting events.

U.S. intelligence officials say the attack shows how easily it could be duplicated elsewhere.

The notice, prepared by the FBI and the Homeland Security Department, cautions there are no known plots against sporting events in the United States.

Days before the attack, Pakistan's government dismissed the opposition-led regional administration based in Lahore as part of a bitter political dispute. Several people have alleged that chaos resulting from that decision could have been a factor in the security lapses.

Lahore commissioner Khusro Pervez said the gunmen should have been battled by "back-up police support which didn't arrive."

"The vehicles used for escorting the Sri Lankan convoy were not adequate," the Dawn newspaper quoted him as saying to a television news show owned by the same media company.

"There are certain security lapses, which are very vivid and very clear," he said.

None of the attackers is believed to be in custody, though on Thursday, authorities said they knew the identity of the assailants.

Punjab Gov. Salman Taseer, who has taken over as the province's chief executive, said authorities "have identified the people who have done this operation. But at this time I don't want to say anything which may create any difficulty."

He added that investigators have found a large number of weapons, made some arrests and identified the culprits. He said he would give more details in coming days.

Salahuddin Niazi, the police official heading the investigation team, said earlier that several people were being questioned in the attack.

"We got some strong clues and leads, and several suspects are in our custody and raids are currently under way to capture more people on information gleaned from some of the detainees," he said.

Islamic militants are widely suspected, but authorities have not explicitly said that.

Pakistan has a web of extremist networks, some with links to al-Qaida and the Taliban, that have attacked foreign civilians in a bid to destabilize the government and punish it for supporting the U.S.-led invasion of Afghanistan.

Broad, the referee, was traveling in a van in the same convoy as the Sri Lankan team bus when the attackers opened fire with automatic weapons, grenades and at least one rocket launcher, killing his driver and critically wounding a fellow official.

"There was not a sign of a policeman anywhere," Broad said Wednesday after flying back to Britain. "They had clearly left the scene and left us to be sitting ducks."

He did not say how he managed to escape.

His remarks earned a rebuke from the head of Pakistan's cricket board.

"There is not a single bit of truth in his statements," said Ijaz Butt, who promised to lodge a protest with the International Cricket Council over Broad's comments. He added that a police commando was wounded in the neck protecting Broad during the attack.

The security lapse was all the more shocking because Pakistan knew any incident would end, perhaps for years, its hopes of regularly hosting international sporting events. Even before the ambush, most teams chose not to visit this cricket-obsessed country because of rising violence by Islamic extremists.

The surveillance video, broadcast on Pakistani television, showed several attackers apparently escaping down a side street on motorcycles while brandishing weapons. Three were shown walking along the middle of the street, apparently in no fear that they were being chased by police.

The assault bore similarities to November's three-day terrorist rampage in the Indian financial capital of Mumbai. The Pakistani group Lashkar-e-Taiba has been blamed for that attack, in which 10 gunmen targeted hotels, a Jewish center and other sites, killing 164 people.

Pakistani authorities have since cracked down on the group, which is based in eastern Pakistan.