LAHORE, Pakistan (Reuters) - Pakistani investigators were following "important leads" to identify who was behind the attack on the Sri Lankan cricket team in Lahore, Foreign Minister Shah Mehmood Qureshi said on Wednesday.
The ambush in broad daylight, and the apparent ease with which around a dozen gunmen escaped after a firefight with police of almost 30 minutes, sent shudders through a world fearful of nuclear-armed Pakistan's inability to contain rising militancy.
"We also have some important leads that would eventually unearth people responsible for this terrible act," Qureshi told a news conference with his Sri Lankan counterpart in Islamabad.
Sri Lankan Foreign Minister Rohitha Bogollagama said this was the first attack on its nationals outside the country and he did not rule out possibility that the rebel Liberation Tigers of Tamil Eelam (LTTE) movement was involved.
Desperate for leads, police rounded up scores of people without establishing any link, according to officials, although one mid-level officer in the probe told Reuters a cellphone had been found that led to the arrest of at least one real suspect.
Seven Pakistanis, including six police and the driver of a bus carrying match officials, were killed in Tuesday's attack on the Sri Lankan team as it was being driven to the Gadaffi Stadium for the third day of a match against Pakistan.
Six Sri Lankan players were wounded along with two team officials, including a British assistant coach. They flew back to Colombo along with the rest of the tour party on Tuesday night.
ICC match referee Chris Broad told a news conference in London he and other match officials had been left like "sitting ducks" by a lack of security.
The Punjab government has offered a reward of around $125,000 for information on the attackers, who were armed with AK 47s, hand grenades and rocket propelled grenades.
Television footage showed gunmen wearing track suits and trainers and shalwar kameez, traditional long shirt and baggy pants. Some appeared to be barely 20 years old.
They appeared to leave the scene of the attack quite calmly, walking and on motor cycles.
Pakistan has reeled under a wave of bomb and gun attacks in recent years, mostly carried out by Islamist militants linked to the Taliban or al Qaeda, but arch nationalists would relish a link being found between rival India and the Lahore attack.
Pakistan's pro-West President Asif Ali Zardari wrote in a column for the Wall Street Journal on Wednesday that the "terrorist attack against the Sri Lankan cricket team in Lahore shows once again the evil we are confronting."
The targeting of a visiting cricket team from a friendly country stunned Pakistanis whose love of the sport only comes second to religion in terms of forging a spirit of unity.
The reverberations were felt across the cricketing world and beyond, with U.S. President Barack Obama expressing deep concern.
U.S. Federal Bureau of Investigation director Robert Mueller held talks with Pakistani officials in Islamabad on Wednesday to follow up on the probe into the Mumbai attacks, having already met with Indian officials in New Delhi.
The United States wants Pakistan focused on fighting terrorism, but there are fears Zardari's civilian government could be engulfed by crises less than a year after taking power.
Aside from militancy radiating across the northwest from the borders with Afghanistan, Pakistan desperately needs billions of dollars of aid to supplement a bailout by the International Monetary Fund last November.
Elections to parliament's upper house, the Senate, were held on Wednesday under the shadow of a political crisis that sparked street agitation in the past week and sent share prices tumbling.
But the Karachi index bounced nearly 4 percent by Wednesday afternoon thanks to support buying from state-run institutions.
There is a long list of possible suspects for the attack in Lahore. The Tamil Tigers are close to defeat in northern Sri Lanka and have a history of deadly guerrilla attacks.
"LTTE definitely, we believe have outside links and international connections to other terrorist organizations but these are matters that we cannot discuss in the open," Bogollagama said.
Speculation has otherwise focused largely on two Pakistani jihadi groups -- Lashkar-e-Taiba (LeT) and Laskhar-Jhangvi (LeJ), as well as the Pakistani Taliban.
LeJ, a Sunni Muslim group, is regarded as a cat's paw for al Qaeda in Pakistan and has been linked to several high-profile strikes including the suicide truck bomb attack that killed 55 people at Islamabad's Marriott hotel last September.
Pakistan has arrested a few LeT members after India and the United States said the group was responsible for the slaughter of about 170 people by gunmen in the Indian city of Mumbai last November. The group is also said to have some links to al Qaeda.
Formed to fight Indian rule in Kashmir, LeT has had good relations with Pakistani intelligence agencies in the past, and there is pressure on Pakistan to cut any remaining jihadi ties.
Several observers noted some similarities between the Lahore and Mumbai attacks.