About 700 students have surrendered at a mosque besieged by Pakistani security forces in the capital, Islamabad, officials say.
Female students have been told they will not be prosecuted
Militant students inside the compound have been told to give themselves up, after fierce gun battles with security forces killed 10 people on Tuesday.
Several thousand people remain inside the Red Mosque (Lal Masjid) complex, many young students at a girls' school.
Clerics at the mosque are campaigning for Islamic Sharia law to be enforced.
'They are children'
Troops sealed off the area around the mosque after Tuesday's clashes and no-one is able to get within about one kilometre of the site.
At daybreak, soldiers strung barbed wire across streets near the mosque, where armed students have barricaded themselves in.
"My two daughters are inside and I am worried about them," one parent, Mohammad Javed, told the BBC. "They are 14 and 10 years old.
"I have talked to them and they are willing to die for Islam. It is the government's fault, they should back down."
Another man said he had been trying to persuade his brother to come out.
"What the students are doing is because they are immature and young... They don't understand the consequences."
An indefinite curfew is in place around the Red Mosque, and power and water supplies have been cut off.
Those inside have been ordered to give up their weapons, although officials have said they do not want more bloodshed.
The BBC's Barbara Plett outside the mosque says it is not clear what will happen to students who do not comply with the ultimatum.
Clerics, acting as intermediaries, held overnight talks with both sides, but there has been no sign of a breakthrough.
At least two deadlines set by the government for students to surrender have passed.
The government has said women and children can go free - with offers of money and safe passage - but top mosque leaders and males involved in killings and other crimes will face prosecution.
Officials say several thousand students remain inside the mosque compound. Our correspondent says security officials estimate that eventually a hard core of several hundred militants will be left.
In addition to those killed, more than 140 people were hurt during Tuesday's violence, officials said.
People fled from busy shopping areas as masked students traded fire with security forces. Dozens of other students - mostly armed with sticks and petrol bombs - patrolled the area.
The mosque and the two religious schools attached to it - one for men, the other for women - have recently been the focus of several confrontations with the Pakistani authorities.
The mosque's male and female students took part in the stand-off
These have been provoked by the kidnapping of police officers and of people accused of involvement in prostitution by members of the mosque.
Critics have attacked the government for failing to enforce its authority in the capital.
President Pervez Musharraf has previously said security forces cannot raid the mosque for fear of reprisal suicide attacks.
BBC correspondents say it is thought the mosque has powerful friends in the security services, which has prevented the authorities from taking action.
But now that people have been killed, the government has finally gone on the offensive.