Pakistani security forces have fired what they describe as a series of "warning blasts" outside a radical mosque in central Islamabad. Officials say more than one thousand "hardcore" religious students remain inside the mosque two days after violent clashes with police left at least 16 people dead. VOA correspondent Benjamin Sand reports from the Pakistani capital.

Officials say the powerful pre-dawn blasts were a wake up call for the militants inside Lal Masjid or Red Mosque.

Pakistani religious students sit under tight security after their surrender to the authority outside the 'Lal masjid' or Red mosque in Islamabad, Pakistan, 05 July 2007

The stand off outside the hard-line Islamist mosque is now entering its third day, and authorities insist time is running out for the militants to surrender.

Hundreds of students have already accepted a government amnesty offer, but officials say thousands more remain inside.

Information Minister Tariq Azim says police have captured the mosque's chief cleric, Abdul Aziz, who was apparently trying to sneak out disguised as a woman Wednesday night.

"We expected there was somebody whose movements were not exactly woman like," said Aziz. "So when we checked he was trying to escape in a burka."

Lal Masjid has been at the center of a months long stand off with government security forces after its leaders vowed to impose strict Taleban-style Islamic law in the capital.