Police claimed the man came from South Waziristan, the district in Pakistan’s lawless tribal belt on the Al-Qaeda-infested Afghan border where the military is pursuing a major operation against the Taliban.

“A double-cabin pick-up came at F-11 checkpost of Islamabad police and dropped off this suicide bomber on the opposite side of the road,” Bani Amin, operations police chief in the capital, told AFP.

“The suicide bomber shouted ‘Allah Akhbar!’ and started advancing towards the checkpost. Police ordered him to stop but he continued advancing. Then police opened fire and killed him.”

The man’s suicide jacket was recovered and police have launched a search for the vehicle that dropped him off. The vehicle is believed to have headed for Islamabad’s sprawling twin city of Rawalpindi, officials said.

Checkpoints have mushroomed in Islamabad in recent months as Pakistan is on high security alert in a bid to thwart Al-Qaeda and Taliban-linked militant attacks, which have killed more than 2,400 people since July 2007.

The would-be bomber appeared to be 34-35 years old and an inhabitant of South Waziristan, Islamabad police chief Kalim Imam said.

“All the bullets hit his head. That is why he was not able to detonate explosives,” he said. “Bomb disposal staff have defused the explosives in the suicide jacket.”

The incident came hours after a suicide car bomber killed 12 people in Pakistan’s northwestern city of Peshawar.