Fazlur Rehman Khalil, a signatory to the 1998 bin Laden declaration of war on the United States and its allies, was severely beaten by eight armed men, supporters said.

The attackers dragged Khalil and his driver from a mosque in Tarnol, about three miles northwest of Islamabad, Pakistan's capital, as they attended evening prayers, said his spokesman Sultan Zia.

Khalil is a former leader of a al-Qaida-linked militant group. The U.S. labeled Khalil's group a terrorist organization in 1994.

Khalil's attackers held him for five hours and beat him with rifle butts before dumping him in front of a mosque on Islamabad's outskirts, supporters said. He was reported in critical condition in a hospital Wednesday night.

In June, the FBI arrested Lodi, Calif., ice cream truck driver Umer Hayat, 48, and his son Hamid Hayat, 23, and charged them with training in one of Khalil's camps in Pakistan for attacks in the United States. The men are on trial in California. The prosecution rested its case Wednesday.

In 1998, President Clinton ordered an attack with 60 Tomahawk cruise missiles on targets including Khalil's camps near the eastern Afghan town of Khowst. It was a failed attempt to kill bin Laden after al-Qaida's attacks on two U.S. embassies in east Africa, which killed at least 224 people.

Intelligence assessments concluded that the missile strikes missed bin Laden by a few hours, but Khalil said several of his fighters were killed.

Pakistani authorities arrested Khalil in 2004 when he was accused of aiding militants crossing into neighboring Afghanistan to attack U.S.-led forces.

He was detained at least two more times, but was always released under what Pakistan's government insisted was close supervision to ensure he didn't engage in militant activities.

As late as 2004, Khalil continued to rally militants to wage jihad, or holy war, against the U.S. in a magazine called Al Hilal, which he published.