Pakistani, Afghan Militant Groups .c The Associated Press

Following are some of the Islamic militant groups the United States is pressuring Pakistan to close down or ban:

HARAKAT-UL-MUJAHEDEEN: Previously Harakat-ul-Ansar, but changed its name after United States declared the group a terrorist organization. Harakat-ul-Ansar was founded by Masood Azhar, one of three Kashmiri militants freed by India last December to end the hijacking of an Indian Airlines jetliner. Harakat-ul-Mujahedeen's leader is Fazal-ur-Rehman Khalil. Headquartered in Pakistan, with a membership believed to be in the hundreds, the group is committed to fighting Indian soldiers in Indian-ruled Kashmir. It's fighters, trained in Afghanistan, are believed to have also fought in the breakaway republic of Chechnya, Bosnia and Algeria.

HARAKAT-UL-JEHAD-E-ISLAMI: The parent organization of Harakat-ul-Mujahedeen, led by Qari Saifullah Akhtar, who spends most of his time in Afghanistan. It is believed to have thousands of fighters, who train in Afghanistan and have fought in Chechnya and Bosnia.

LASHKAR-E-TAYYABA: Led by Hafiz Mohammed Saeed, it is based in Muridke, in Pakistan's eastern Punjab province, and has a membership in the thousands, who are trained in Afghanistan and in Pakistan-ruled Kashmir.

AL QAIDA: Led by Osama bin Laden, Al Qaida is committed to forcing the United States to withdraw its army from Saudi Arabia, where two of Islam's holiest sites are located. Its membership figure is unknown but bin Laden is believed to have thousands of followers. His popularity soared after 1998, when the United States fired Tomahawk cruise missiles at eastern Afghanistan where bin Laden is believed to operate military training camps. Bin Laden, a millionaire Saudi, also raises millions of dollars from sympathizers throughout the Muslim world. Al Qaida members fight alongside the Taliban in Afghanistan and reportedly train militants to fight in Indian-held Kashmir. Al Qaida also is known to have sent fighters to Chechnya, Bosnia and Kosovo.