Islamabad: More than 500 radical Muslim students surrendered at a besieged mosque in the Pakistani capital on Wednesday but thousands of militants remained inside
a day after 11 people were killed in clashes.

Hundreds of soldiers and police sealed off the mosque and imposed a 24-hour curfew after Tuesday's bloodshed, as the government extended a deadline for students to lay down arms.

The violence erupted after a months-long stand-off between the authorities and a Taliban-style movement based at Lal Masjid, or Red Mosque, less than a couple of kilometres from parliament and Islamabad's protected diplomatic enclave.

Soldiers moved 12 armoured personnel carriers, mounted with machine guns, into the area as gunfire subsided overnight.

Growing numbers of students took up an offer of safe passage and 5,000 rupees ($85) and left the mosque as a deadline for students to surrender passed at 1.00 p.m.

More than 500 people, 100 of them women and children, had left the mosque but between 2,000 and 5,000 people remained inside, officials said.

The men who surrendered were herded onto trucks while women and children were released.

Liberal politicians have for months pressed President Pervez Musharraf to crack down on Lal Masjid's clerics, who have threatened suicide attacks if force was used against them.

Deputy Interior Minister Zafar Warraich told an earlier news conference anyone who tried to fight would be shot.

"A bullet will be responded with by a bullet," he said.

The violence comes at a bad time for Musharraf. He is preparing for presidential and general elections and is already struggling to dampen a campaign by lawyers and the opposition against his suspension of the country's top judge in March.

Overnight, power was cut off to the compound and surrounding neighbourhood and barbed wire laid across junctions.