FACTBOX: Wanted by India, living in Pakistan

(Reuters) - Ratcheting up diplomatic pressure on Pakistan in the wake of the attacks on Mumbai, India has demanded that Islamabad hands over 20 most-wanted criminals and militants.

Among the most notorious are Dawood Ibrahim, a reputed gangster with suspected militant links; Maulana Masood Azhar, the head of feared militant group Jaish-e-Mohammad; and Hafiz Saeed, founder of Lashkar-e-Taiba, the group suspected of launching the Mumbai attacks.

Here is are brief profiles on the three men:

DAWOOD IBRAHIM

-- India's most wanted man for his part in the country's most deadly bombings, the 52-year-old underworld boss eluded authorities for the past 15 years. He is believed to be hiding in Pakistan.

-- In 1993, Ibrahim, and his brother Anis, allegedly masterminded India's worst bombings, which killed at least 250 people and wounded more than 700 in Mumbai.

-- Some Muslims are said to see Ibrahim as a hero who stood up for India's Muslim minority because he reportedly ordered the blasts in retaliation for Hindu-Muslim riots in Mumbai.

-- The son of a lowly police constable, Ibrahim was a police informant from a young age. By the 1980s and 1990s, he had graduated from petty crime to become one of Mumbai's top gangland leaders, with a billion-dollar vice empire spanning gambling, drugs and prostitution.

-- In October 2003, the United States designated Ibrahim as a global terrorist with links to Islamist militant groups al Qaeda and Lashkar-e-Taiba. The U.S. Treasury froze his assets, and accuses him of drug-running to western Europe and Britain.

-- In July 2005, his daughter Mahrukh married the son of top Pakistani cricketer Javed Miandad in a high society wedding in Dubai. Ibrahim did not attend.

-- Ibrahim was mysteriously spirited away after reportedly being wounded in gunfight at a Karachi hotel in August, 2007.

MAULANA MASOOD AZHAR -- First came into the international spotlight in December 1999 when India was forced to free him from jail along with two other militants, in exchange for the release of crew and passengers of an Indian Airlines plane that had been hijacked from Kathmandu in Nepal and taken to Kandahar in Afghanistan.

-- Born in the southern Punjab district of Bahawalpur in 1968, Azhar was educated at Karachi's Jamia Binoria, a madrasa, or religious school, known for recruiting fighters for the war against the Soviet occupation of Afghanistan in the 1980s.

-- Azhar fought in Afghanistan, but really made his mark in writing propaganda and making speeches in support of the cause.

-- Unconfirmed reports say he surfaced in Sudan, Somalia and Yemen and had contact with Osama bin Laden in the early 1990s.

-- He became a leader of the Pakistani militant group Harkat-ul-Mujahideen. In 1994 he was captured in Indian Kashmir, and tried for terrorism. Although acquitted, he spent six years in jail until he was sprung by the hijacking.