Gunmen fired at Pakistani President Pervez Musharraf's aircraft as it took off on July 6, while a radical cleric holed up in an Islamabad mosque just kilometers away with hundreds of followers said they would die rather than surrender.

There was no indication the attack on Musharraf's plane - which took off from a military base next to Islamabad International Airport - was connected with the siege at the Red Mosque, but it added to a sense of foreboding over risks posed to Pakistan's stability by Islamist militants.

Adding to a sense of crisis, a suicide bomber killed six soldiers in a northwest region where the hardliners in the Islamabad mosque have many allies.

The military at first denied there had been an attack on the president, but later called a news conference. An intelligence officer, speaking on condition of anonymity, said there had been an unsuccessful attempt on Musharraf's life.

Musharraf, a US ally who took power in a military coup in 1999, survived two assassination attempts by al Qaeda-linked militants in Rawalpindi in December 2003.

An anti-aircraft gun and a light machine gun were mounted on the roof of a two-story house under the flight path of the main runway used by civilian and military aircraft.

Security is normally deployed ahead of presidential flights, and the timings are kept secret. Security forces cordoned off the the house, and the owner - a shopkeeper - was detained. A neighbor reported hearing firing from the roof.

Musharraf has not commented publicly on the siege at Islamabad's Red Mosque, but has urged security agencies to be patient and allow maximum time for parents to take children out of a madrassa, or school, in the mosque compound. At least 19 people have been killed in clashes that erupted outside the mosque on July 3, and the compound housing the mosque and madrassa has been under siege by hundreds of troops and police. Water, gas and electricity supplies have been cut.