A suspected suicide attack targeting police deployed at a rally to mark the first anniversary of the bloody storming of Pakistan's Red Mosque killed at least 11 policemen yesterday, officials .said.

The powerful explosion happened just after thousands of Islamist hardliners had called for the public hanging of President Pervez Musharraf at the angry protest in the capital Islamabad.

More than 100 people were killed in the siege and storming of the al-Qaeda-linked mosque by government troops in July 2007 and the raid sparked a wave of suicide attacks across the country.

"We have 11 policemen dead

and it appears to be a suicide attack," the senior security official told AFP, adding that dozens of other people were wounded.

"The blast happened 15 minutes after the meeting dispersed. A heavy contingent of police was at a main crossing several hundred metres from the mosque and they were targeted in the attack," the official said.

Television footage showed^ bearded students frantically running towards the scene of the explosion and ambulance crews bringing the wounded to hospitals.

Police officer Masood Ahmed said eight policemen were confirmed dead so far and that the toll was expected to rise.

Earlier Islamic students from

across the country thronged outside the radical mosque amid tight security by thousands of police who erected 1 barbed wire barricades to stop vehicles entering the area.

Police also set up pickets and searched people for arms.

In fiery speeches, Islamists condemned the 2007 military operation against the mosque, blaming Musharraf for the carnage, which they claimed was carried out at the request of the United States.

"Musharraf, then interior minister Aftab Sherpao, and others who were responsible for the bloodbath should be tried and hanged publicly," Islamist leader Idrees Haqqani said as the crowd raised their hands in approval.

The speakers also called for jihad (holy war) against so-called infidel forces, including US and Nato troops fighting militants in Afghanistan.

The crowd shouted "revenge, revenge" as speakers blamed Musharraf for launching the raid as part of a "US crusade" against Muslims.

An official from an organisation of madrassas said a murder charge should be brought against Musharraf and all those who took part in the operation.

"A criminal case of mass murders should be registered against Musharraf and others responsible for the killings," Hanif Jalandhri told the crowd.

Speakers also threatened unspec -ified action if the mosque's jailed leader. Abdul Aziz, who was caught fleeing in a woman's burqa on the second day of the siege, was not released.

In a resolution, the rally announced that they would move to re-open a female seminary destroyed in die operation, and demanded the government hand back control of the complex to its former administration.

The female students from the seminary became a symbol of the hardline mosque's defiance last year, and it was their kidnapping of several Chinese nationals allegedly invoked in prostitution that sparked the dcadlysiege.