The Lashkar-e-Taiba, or Army of the Righteous, consists of mostly radically religious Pakistanis and is said to have been born out of an ultra-orthodox version of Sunni Islam.
Formed in the mid-1990s, the group has claimed responsibility for most of the daring guerrilla attacks against civilian and military targets in Indian-administered Kashmir since 1999.
The group, which was banned in Pakistan in 2002, is also said to have been responsible for the 2001 Indian Parliament attack, and most notably, the 2008 Mumbai attacks.
The LeT is said to have trained 10 of the gunmen involved in the attacks in Mumbai, which resulted in the deaths of 166 people.
Lashkar-e-Taiba and al-Qaeda operate separately but US analysts claim they help each other when their paths intersect.
Current Lashkar-e-Taiba (LeT) leader Hafiz Muhammad Saeed is an academic who turned towards fundamentalist activism in the early 1990s.
Saeed is wanted by the United States, India and the United Nations as a terrorist leader but he operates openly in Pakistan, giving public speeches and appearing on TV talk shows. The US has offered a $10m reward for the capture of Saeed.
The 62-year-old leader has also proudly declared that he and al-Qaeda leaders Osama bin Laden and Ayman al Zawahri had the same teacher.
|Hafiz Saeed was placed under house arrest in Pakistan for a one-month after the Mumbai bombings [AFP]
Despite allegations of terrorism, Saeed maintains that he has no connection to the LeT and is instead the head of Jama'at-ud-Da'wah, which he considers a charitable organisation.
The US declared Jama'at-ud-Da'wah a foreign terrorist organisation in 2008, saying it is front for LeT.
Da'wah, which is one of Pakistan's biggest charities and known across the country for its relief work after a 2005 earthquake in Kashmir, has long denied all terror accusations.
The LeT has said that militant forms of jihad are "absolutely obligatory" both in self-defence and in response to what they believe to be injustice or oppression towards Muslims the world over.
In practice, Lashkar's theatre of operations has been largely confined to Indian-administered Kashmir.
In a pamphlet entitled "Why Are We Waging Jihad?" the group said it aimed for the restoration of Islamic rule over all of India. It also declared India, Israel and the United States as existential enemies of Islam.
However, the group in 2009 publicly declared that it is seeking a peaceful resolution in the Kashmir conflict and that it does not have global jihadist aims.
However, India and the US believe Lashkar-e-Taiba is still active and has a hand in several anti-Indian operations.