At least 24 people have died in clashes in the past week after gunbattles broke out between security forces and supporters of hard-line clerics who have tried to impose Taliban-style rule in the capital.
After a botched commando raid on the high-walled compound at the weekend, President Pervez Musharraf assigned ex-premier Chaudhry Shujaat Hussain to try to negotiate a peaceful end to the stand-off.
“We have come here to play our role to resolve the issue. We hope that all these women and children who are inside should be allowed to come out,” Mr Hussain told reporters as he led a delegation of negotiators including several religious leaders through an army cordon toward the mosque.
Information Minister Mohammed Ali Durrani said later the negotiators had contacted mosque leader Abdul Rashid Ghazi using loudspeakers and a cell phone rather than entering the mosque because of concern for their safety.
Six parents who had entered the mosque to look for their children had not returned, Mr Durrani said.
“The basic strategy of the government is to rescue maximum number of people,” said Mr Durrani.