ISLAMABAD : Thousands of Islamist hardliners converged amid tight security in the Pakistani capital on Sunday to commemorate the first anniversary of the deadly siege and storming of the Red Mosque, officials said.

Religious leaders were set to address a crowd in front of the building, where they would call for the release of the mosque's jailed leader and for the government to hand back control of the complex to its former administration.

Pakistani troops surrounded the radical mosque on July 3, 2007 after clashes with Taliban and Al-Qaeda militants holed up inside, and stormed it one week later. More than 100 people were killed during the operation.

"There will be thousands of people, students from madrassas holding a day-long conference outside the mosque," Qari Abdul Rashid, protest organiser and convenor of the Lal Masji (Red Mosque) Action Committee, told AFP.

He said they would press the government to free mosque leader Abdul Aziz, who was caught fleeing in a woman's burqa on the second day of the siege, and to rebuild an adjoining girls' Islamic school demolished after the crisis.

The protesters would also call for students to be allowed back to a boys' madrassa in a separate part of Islamabad and urge authorities to "restore Lal Masjid's old status."

"We will remain peaceful and it will be an impressive show," Rashid said.

Organisers said that thousands of students from around the country had arrived in Islamabad overnight, with some of them camping out near the mosque, and that around 10,000 to 15,000 people would attend on Sunday.

Security officials told AFP they expected around 7,000 to 8,000 participants and added that they had taken extra measures to ensure the rally passed off peacefully.

"We have beefed up security in the city, diplomatic missions and government installations will be protected. Nothing is being left to chance," a senior security official said on condition of anonymity.

The storming of the mosque unleashed a wave of Taliban suicide bombings across the country that left around 1,000 people dead and was cited by President Pervez Musharraf in declaring a state of emergency in November.

Opinion remains divided over the operation in Pakistan and conspiracy theories continue to rage over the death toll.

Pakistan's new government signed a peace deal with Taliban militants near the Afghan border after winning February elections, but went ahead in the past week with an operation against radicals near Peshawar.

Islamabad has been under mounting pressure from Washington to live up to its partnership in the US-led "war on terror" and crack down on extremist fighters with bases in Pakistan's troubled Pashtun tribal areas.

- AFP/vm