Government forces tightened the noose on day six of the siege of the Red Mosque, after a top commando died in an operation to blast through the wall around the complex and allow the alleged "human shields" to escape.

Officials said some foreign rebels were barricaded in the building, along with Pakistani militants from a group linked to the beheading of US journalist Daniel Pearl and attempts to kill President Pervez Musharraf.

Religious Affairs Minister Ijaz-ul Haq said the government believed the mosque's firebrand deputy leader, Abdul Rashid Ghazi, had effectively been deposed by the extremists.

"The hardcore militants are in control of the mosque," Haq told AFP. "Our fear is that they may start killing the women and children to press for their demand for safe passage."

Haq said that one or two militants from Uzbekistan were among those believed to be in the mosque.

Uzbeks, Arabs and Chechens formed the backbone of an al-Qaeda force that fled into Pakistan's troubled tribal areas after the US-led invasion of neighbouring Afghanistan following the 9/11 attacks in the United States.

Military ruler Musharraf and Prime Minister Shaukat Aziz spoke by telephone on Sunday to weigh up the government's options after so far delaying a raid on the mosque.

"They have discussed how to bring the crisis to a swift end, including possible assault on the compound," a top official familiar with the issue told AFP.

Musharraf, who on Saturday told the militants to surrender or be killed, earlier attended the funeral of Colonel Haroon Islam, the elite commando killed in the clashes overnight.

Security officials and a source inside the mosque said militants from the banned Pakistani group Harkatul-Jihad-e-Islami were now in command there and putting up "fierce resistance".

"We believe there are militants from Harkatul-Jihad-e-Islami, which was involved in the Pearl murder. Based on intelligence we suspect that two commanders from the group are in there," one senior official told AFP.

The organisation sheltered al-Qaeda militants who fled Afghanistan after the fall of the Taliban. Its former chief, Amjad Farooqi, played a key role in Pearl's 2002 beheading and a 2003 attempt to assassinate Musharraf.

A mosque source identified the leader of the Harkatul-Jihad-e-Islami militants in the mosque as Abu Zar, a former accomplice of Farooqi.

There was "lot of tension among the various groups inside the compound on how to conduct the fight," the source added on condition of anonymity for fear of his own safety.

Twelve female students are on a hunger strike and have demanded to leave the besieged complex, while several others died in clashes on Sunday, the source said. Militants also shot at the legs of three girls who escaped.

Ghazi remained defiant.

He and his followers have written wills saying that they will die rather than surrender, and that "martyrdom" will spark an Islamic revolution in extremism-hit Pakistan, a source at the mosque told AFP.

"Our blood will not go to waste," the will said.

Ghazi told local television that 335 people inside the mosque were killed in Sunday's latest fighting.

Information Minister Tariq Azeem dismissed the "laughable" claim and said the death toll from the entire siege was 24.

Ghazi, 43, signalled his defiance on Saturday by saying that he was telephoned by a man who claimed to have shot at Musharraf's aircraft on Friday in revenge for the siege.

Security officials said earlier they were probing possible links between the mosque operation and the failed bid to shoot down the president's plane as it took off from Chaklala military airbase at Rawalpindi, near Islamabad.

Students affiliated to the mosque have irked the government since January with a Taliban-style anti-vice campaign, which has involved the abduction of several people they linked to prostitution, including seven Chinese.