The chief cleric of the radical mosque under siege in Islamabad was arrested yesterday as he tried to flee disguised in a woman’s burka.

Abdul Aziz, the prayer leader of the Lal Masjid, or Red Mosque, was hiding among about 60 women fleeing the mosque’s female madrassa. His wife, who had threatened to launch suicide attacks against the security forces surrounding the mosque, was also arrested.

Hopes that the arrest of the hard-line mullah would lead to a peaceful end to the siege appeared to be shattered last night, when gunfire and loud explosions were heard coming from the area of the mosque. 16 people have already died in bloody clashes between Pakistani forces and the Islamic militants holed up inside.

Pakistani troops tightened the cordon around the mosque throughout the night, after the militants defied a government deadline to give themselves up. The troops were ordered to shoot on sight and a curfew was imposed in the central district.

Armoured cars surrounded the Lal Masjid, which is located a few blocks away from the parliament and presidential palace and close to the headquarters of Inter Services Intelligence, the country’s top spy agency.

About 700 pupils of the seminary attached to the mosque surrendered after the electricity and water supply were cut off. The Government offered £40 to students who left the mosque, but more than 2,000 heavily armed militants, including a large number of women, remained defiant.

Marriyum Qayum, a 15-year-old female student, who came out of the madrassa wrapped in a black burka, said: “They want to die as martyrs.” She said that they were running out of food supplies.

For the past six months the militants have challenged the Government of President Musharraf by attempting to establish a Taleban-style Sharia system in the capital. Many of the students come from tribal areas of the North West Frontier Province bordering Afghanistan.

The stand-off intensified when the clerics established Islamic courts and their supporters raided houses, dragging out women who they alleged were involved in prostitution.

The situation came to a head last month when they raided a massage parlour and abducted about half a dozen Chinese women.

Moderate Pakistanis had expressed frustration over General Musharraf’s reluctance to take action against the militants.

Government forces claimed that one reason for their inaction was the fear of causing the deaths of dozens of innocent bystanders. More than 3,000 female students, some as young as 5, lived in the seminary and were used as human shields against any threat of the use of force. Leaders of the mosque also threatened to launch suicide attacks.

The radical clerics are said to have close links to al-Qaeda and the Tale-ban militants who operate in Pakistan’s lawless tribal region close to the border with Afghanistan. Abdul Rash-id Ghazi often boasted that he was a follower of Osama bin Laden. He was detained by the security forces in 2004 for his involvement in terrorist activities but he was freed on the intervention of a federal Cabinet minister.

Pakistani security officials said that the mosque had become the centre of outlawed militant groups who had also been involved in terrorist attacks targeting foreign nationals.

A confidential report by Pakistan’s Interior Ministry gave warning that Talebanisation in the northern region presented the biggest threat to the country’s security. The Lal Masjid movement was regarded as part of the religious extremism creeping into cities from the frontier region.

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