The Pakistani government on Saturday sealed the troubled Lal Masjid in Islamabad, a day after a suicide attack killed 15 people during clashes between Islamic extremists and security forces following its reopening.
Hundreds of policemen set up new checkpoints and cordoned off the area around the compound with barbed wire. "The mosque will now remain closed for an indefinite period," Interior Ministry spokesman Javid Cheema said.
Security in Islamabad was also strengthened to thwart possible attacks by Islamist radicals.
Police were deployed at all entry and exit points of the capital and the nearby city of Rawalpindi, where security forces were put on high alert.
The authorities had carried out reconstructive surgery of the head of the suspected suicide attacker to make his face recognisable, while other parts of his body were sent to the laboratory for DNA testing.
The bombing targeted a group of policemen deployed near the Red Mosque to quell an irate mob of some 2,000 Islamic theology students who occupied the compound for several hours after it reopened for Friday prayers.
The police used tear gas to disperse the crowd and arrested around 100 rioters as it regained the control of the mosque compound.
Earlier this month, the state authorities launched a security operation at the mosque after a five-month standoff with students over their violent campaign to enforce Taliban-style Islamic law in Islamabad.
Extremists have launched a series of attacks in recent weeks to avenge the mosque operation, killing more than 100 people.