Witnesses say loud explosions were heard early Thursday at a besieged radical mosque in Pakistan's capital, Islamabad.
The blasts came after two days of clashes between hardline religious students and security forces at the Lal Masjid, or Red Mosque, left at least 16 people dead
On Wednesday, Pakistani officials said the head of the mosque was detained while trying to flee, disguised in a burqa. Security forces seized Abdul Aziz as he tried to leave the mosque in a crowd of women wearing similar attire.
More than one thousand of his followers surrendered to authorities Wednesday. But some supporters remained holed up in the mosque.
The government ordered militants to lay down their arms or face further attacks. Pakistani troops have sealed off the area around the mosque and have imposed a curfew in Islamabad.
At least 11 people were killed in clashes with security forces Tuesday.
Clerics and students have been challenging the government with demands for strict Islamic law.
Pakistani officials say those killed Tuesday included a soldier, a cameraman and four students. More than 80 other people were wounded.
Authorities say the fighting erupted when students from the mosque, many with bamboo clubs and handguns, rushed toward a security post.
Information for this report is provided by AP, AFP, and Reuters