Testimony given to Indian investigators by David Headley, an American Pakistani arrested in Chicago last year, has cast fresh light on the Lashkar-e-Taiba militant group blamed for the November 2008 attack on Mumbai.
Headley said he scouted out targets in Mumbai for the group and later worked with an al Qaeda-linked militant commander to plot an attack in Denmark. His testimony suggests some Lashkar-e-Taiba cadres are being drawn into the orbit of al Qaeda.
Here are some details about the group.
The group has its roots in the Markaz ad-Dawat wal-Irshad (MDI), an organisation created in the mid-1980s to support the jihad, or holy war, against the Soviet Union in Afghanistan and to provide Islamic charity and spiritual guidance.
It follows a Salafist religious tradition known as Ahl-e-Hadith, a minority sect which says it emulates the ways of the Prophet Mohammad. This distinguishes it from the Deobandi tradition of the Taliban and other Pakistan-based militants.
The MDI split into two wings:
-- Lashkar-e-Taiba (LeT) is its military wing. Founded in 1990, it began operations in Indian Kashmir in 1993.
-- Jamaat ud-Dawa (JuD) is its humanitarian wing. It provides extensive education, healthcare and disaster relief.
While their military focus has been on Kashmir, their ideology is pan-Islamic. They are based in Punjab province and in Pakistani Kashmir.
The LeT is officially banned in Pakistan.
The JuD, which denies it still has links to the LeT, was blacklisted by the United Nations following the Mumbai attack.
The JuD now carries out disaster relief under a different name, the Falah-e-Insaniyat. It has been active in providing relief to victims of Pakistan's floods.
It also runs a large educational complex at Muridke near Lahore. The MDI's founder, Hafez Saeed, is a former professor.
OPERATIONS IN THE WEST
The JuD in particular has support and funding from the Pakistani diaspora, often in the form of donations for its charitable work. Analysts say it could exploit this network for attacks on the West.
Among operations linked to LeT were:
-- The Virginia Jihad Network broken up by U.S. authorities and accused of providing support to Lashkar-e-Taiba.
-- French police investigated a British-Pakistani living in Paris for allegedly helping "shoe-bomber" Richard Reid in December 2001. Police failed to prove the case against him, but he was convicted and jailed for recruiting for LeT.
-- Frenchman Willy Brigitte was convicted of involvement in planning attacks in Australia after spending several months in an LeT training camp in 2001/2002.
-- One of the London suicide bombers in 2005 had briefly visited Lashkar's Muridke headquarters, though police found no evidence of the group's involvement in the attack.
-- David Headley, an American arrested in Chicago last year, has pleaded guilty to working with LeT to plot attacks in India, including surveillance of targets in Mumbai.
OPERATIONS IN INDIA
LeT's main focus is on Kashmir and India. Among its operations, alleged or claimed, are the following:
-- It trained and armed hundreds of young men to fight in a separatist revolt in Indian Kashmir which began in 1989.
-- Expanding the war to India, it was involved in a string of gun and bomb attacks on Indian towns and cities, including an assault on the historic Red Fort in New Delhi in 2000.
-- It was blamed for a raid on the Indian parliament in December 2001, but many analysts attribute this attack to another Pakistan-based militant group, the Jaish-e-Mohammad.
-- Its biggest operation was the three-day assault on Mumbai in November 2008 which killed 166 people.
-- Lashkar is believed to have built a network of sleeper cells in India, capitalising on the anger of some Indian Muslims about perceived injustices by the Hindu majority.
OPERATIONS IN AFGHANISTAN
The group has not been heavily involved in the Taliban-led campaign against western forces in Afghanistan, but is believed to operate in Kunar and Nuristan in the east of the country.
Indian analysts also suggested it was involved in an attack on Indian interests in Kabul in February 2010.
Pakistani security officials say any militants operating in Afghanistan have broken away from the main organisation.
In the past, the LeT has been close to the Pakistan army and the Inter-Services Intelligence (ISI) agency. It is the only Pakistan-based militant group believed not to have staged attacks inside the country.
Pakistani security officials have said Pakistan is reluctant to act more forcefully against the group since this would create a new enemy at a time when it has already been fighting the Pakistani Taliban in the tribal areas bordering Afghanistan.
They also say that more forceful action could drive the LeT into a dangerous coalition with the Pakistani-Taliban and al Qaeda-linked militant groups.
Pakistan has arrested seven men over the Mumbai attack, but rejected Indian demands that its leader Hafez Saeed be arrested.
The Jamaat-ud-Dawa first won popular support for its quick relief after an earthquake in Pakistani Kashmir in 2005, and for its work in providing education and healthcare.
(Reporting by Myra MacDonald, editing by David Stamp)