FACTBOX: Who are the Lashkar-e-Taiba?

(Reuters) - Indian investigators said Monday the militants who attacked Mumbai underwent months of commando training in Pakistan, raising tensions between the nuclear-armed neighbors as recriminations mounted in India.

The Pakistan based militant group, Lashkar-e-Taiba, has denied being behind the Mumbai attacks and said it condemned them. However a police officer close to the interrogation told Reuters that the training was organized by Lashkar, and conducted by a former member of the Pakistani army.

Here are some details about the group:

* WHO ARE THE LASHKAR-E-TAIBA?

-- Lashkar-e-Taiba - "The army of the pure" - was a militant offshoot of Markaz Dawatul Irshad, an Islamic charity and educational organization. Markaz Dawatul Irshad has since been renamed as Jamaat-ud-Dawa that was at the forefront of relief work after the 2005 earthquake killed 73,000 people in Pakistani Kashmir and the North West Frontier Province.

-- The Pakistan-based Lashkar made its name fighting Indian rule in Kashmir.

-- It was founded in 1989 by Hafiz Mohammad Saeed and Zafar Iqbal. Saeed was a former teacher of Islamic studies at Lahore's University of Engineering and Technology.

-- Lashkar based its philosophy on Wahhabism, the austere brand of Islam practiced in Saudi Arabia, and has relied on donations from overseas.

-- The group's objective is to Islamicise South Asia with its main aim being to free Muslims in India administered Kashmir.

* WHAT HAVE THEY DONE?

-- The militant group rose to prominence after it carried out attacks across the Himalayan region in 2000/2001. It claimed responsibility for the attack on an army base in New Delhi's historic Red Fort which killed three in late 2000. It also claimed responsibility for an attack on Srinagar airport in January 2001 that killed five Indians along with six militants and an attack in April 2001 against Indian border security forces.

-- In December 2001 gunmen raided India's parliament killing 14 people. India accused the Pakistan-based Jaish-e-Mohammad and Lashkar-e-Taiba groups of being responsible. It was this incident that nearly brought India and Pakistan to the brink of a fourth war. Lashkar denied it was involved.

-- The group was blamed for bomb attacks on markets in New Delhi that killed more than 66 people in October 2005 although they denied it at the time.

COUNTER MEASURES:

-- Pakistan President Pervez Musharraf banned the two groups accused of the attack on India's parliament in January 2002. It had already been banned in India in October 2001 and was also designated as a "foreign terrorist organization" by the

U.S.