Who could have attacked Sri Lanka's cricketers?

Gunmen attacked a bus carrying the Sri Lankan cricket team in the Pakistani city of Lahore today, wounding six players, officials said.

A senior Pakistani official said the raid bore the hallmarks of the same militants who attacked India's financial capital Mumbai in November. India and the United States blamed the militant group Lashkar-e-Taiba for the three-day assault on Mumbai.

The following are the major militant groups operating in Pakistan who could be behind the attack.

LASHKAR-E-TAIBA

Lashkar-e-Taiba or "army of the pure" is one of the largest Islamic militant groups in South Asia, based in Pakistan and fighting Indian rule in Kashmir. Security analysts say it is a well-funded and highly organised group that sympathises with al-Qa'ida.

A charity linked to the group was headquartered at Muridke town, outside Lahore, and most LeT fighters were drawn from surrounding Punjab province. Pakistan raided the group and shut down the charity after it came under pressure from India following the attacks in Mumbai in which nearly 170 people were killed.

India charged the group's founder Hafiz Mohammad Saeed and other senior members Zaki-ur-Rehman Lakhvi and Zarar Shah for the attack. The group denied it was involved.

TEHRIK-E-TALIBAN

The Tehrik-e-Taliban is led by Baitullah Mehsud, an al-Qa'ida ally, and has been accused of being behind a wave of suicide attacks that have rocked Pakistan since mid-2007, including one that killed former prime minister Benazir Bhutto in December 2007. The Tehrik-e-Taliban or Movement of Taliban, Pakistan, is a loose umbrella group of factions based in northwest Pakistan. Mehsud is based in the South Waziristan region. He is fighting to establish a puritanical Islamic society based on Sharia law.

JAISH-I-MOHAMMAD

This group, led by Maulana Masood Azhar, was banned along with Lashkar in 2002 following an attack on the Indian parliament. Like LeT, it carried out suicide attacks in Kashmir, but it has also been named for attacks in Pakistan. In March 2002, a Jaish fighter killed four people, including two Americans, in an attack on a church in Islamabad.

A Jaish connection was made to one of the assassination attempts on then President Pervez Musharraf in December 2003, and there was a Jaish presence at the Red Mosque uprising in Islamabad in 2007. Jaish members have also surfaced in tribal areas bordering Afghanistan. Pakistan said Masood was among those detained following the November attacks on Mumbai, but then denied he was being held.

BALUCH GROUPS

Several guerrilla groups are waging a low-key insurgency in gas-rich Baluchistan province on the border with Afghanistan. Some have taken responsibility for small attacks in Lahore in the past. A group calling itself the Baluchistan Liberation United Front (BLUF) claimed responsibility for the kidnapping of an American working for the United Nations a month ago. The attack on the Sri Lankan team is on a vastly different scale to anything carried out by any Baluch group.

OUTSIDE PAKISTAN - SRI LANKA'S TAMIL TIGERS

In Sri Lanka, official suspicion will fall on the Liberation Tigers of Tamil Eelam (LTTE), a rebel group close to military defeat in northern Sri Lanka and which has a long history of carrying out deadly guerrilla attacks. There has been no clear evidence the Tigers have operations or links to Pakistan.

Pakistan has good relations with Sri Lanka and has given training and supplied arms to the Sri Lankan military fighting the Tamil Tiger rebels.