Pakistan government spurned attempts by radical clerics of the Lal Masjid in Islamabad to work out a negotiated settlement and asked them to surrender along with weapons as the toll in the standoff between security forces and militant mosque students climbed to 21.

Sporadic firing, which continued throughout Tuesday night and Wednesday morning resulted in the death toll mounting to 21, local channel Aaj TV quoted hospital sources as saying.

Over 150 people have been injured.

Meanwhile, the government showed little inclination to attempts by Lal Masjid clerics to work out a negotiated settlement for a conditional surrender through Islamic scholars.

In a stern action, the government arrested member of senate of the Islamist alliance Muttahida Majlis-e-Amal, Mian Aslam, on Wednesday morning under maintenance of public order for his repeated attempts to arrange a negotiated settlement with clerics to end the standoff.

There was no favourable response from Pakistan Prime Minister Shaukat Aziz to MMA general secretary Fazlur Rehman's attempts to arrange a conditional surrender of the clerics.

Earlier, administrator of the mosque, Abdul Rashid Ghazi said he was willing to cooperate with Rehman to end the stand off and even hinted that they would consider giving up before a counsel of Islamic clerics under certain conditions.

Rehman quoted Aziz as saying, 'the orders for action against Lal Masjid management have been issued and the reversal is quite difficult.'

The prime minister has, however, assured him of his cooperation, Rehman told GEO TV.

The government, while deploying the contingent of 111 brigade of the army trained for such operations, served a deadline for the clerics and the militant students to surrender by 1130 hours on Wednesday.

The deadline was for the 'mosque administration to surrender, hand over their weapons' to troops outside the Lal Masjid, Information Secretary Anwar Mehmood told media persons in Islamabad.

"The men who surrender will be ensured safety," he said.

The government also allowed families of some students to go inside the mosque and talk to their wards.

After a day-long standoff on Tuesday, President Pervez Musharraf [Images] had late Tuesday night ordered the deployment of army units around the mosque and the boys madrassa located in a posh locality about 70 km from the Lal Masjid.

The troops were deployed after the government issued shoot at sight orders and served an ultimatum for surrender with their weapons.

Despite the deployment of hundreds of troops with two dozen armoured personnel, Ghazi spoke to different television channels, showing his usual defiance but at the same he admitted that he was in touch with Rehman to negotiate a deal to end the stand off.

Troops cordoned off the area around the Lal Masjid and imposed the curfew, preventing media personnel from going close to the mosque.

Government officials believe that Lal Masjid clerics are trying to buy time.

Musharraf, who approved the army action after a prolonged meeting with top officials, has already said the madrassa housed several militants of the banned Jaish-e-Muhammad outfit.

Announcing the decision of a high-level meeting presided over by Musharraf, Minister of State for Interior Zafar Iqbal Warriach said security forces would hit back at anyone who violated the curfew and tried to attack them but they would not attack the militants on their own.

The curfew was confined to the area around the masjid in central Islamabad but the government has asked people residing in other areas to stay indoors. Warriach said the decisions of the government would be conveyed to the several hundred militants and the two radical clerics, Abdul Aziz and Abdul Rashid Ghazi, who were also brothers to surrender through the loudspeakers.

"We want them to surrender immediately. They should surrender, vacate the Lal Masjid seminary and the public library. Action would continue till they give up the illegally occupied land," Minister of State for Information Tariq Azim said.

"Hopefully, this will not take long," he said, adding that Musharraf has given a go ahead for operation. He said the decision has been taken exhausting all options. The action was announced after middle-rung leaders of the Islamist alliance MMA held unsuccessful talks with the clerics to end the standoff.

Ahead of the announcement, power was cut off to the entire area of the Lal Masjid.

This was followed by heavy slogan shouting from within the campus of the Masjid, which managed to retain power by switching on its generators.