Pakistani security forces have launched an assault on militants who have been holding Islamabad's Red Mosque for the past week. The operation began just before dawn, after negotiations broke down. From Islamabad, VOA correspondent Benjamin Sand reports at least eight soldiers and 50 militants have been killed and officials say they expect the death toll will rise significantly.

Smoke rises from Lal Masjid during heavy gunbattle between Pakistan troops and militants in Islamabad, 10 July 2007

Huge explosions rocked Islamabad's Red Mosque as security forces blasted their way into the heavily armed compound. By mid-afternoon officials said more than two-thirds of the sprawling complex had been cleared.

Hundreds of women and children remain unaccounted for and officials fear many are being used as human shields.

Heavy combat continued throughout the day, as around 50 to 60 militants remained barricaded inside a basement.

Military spokesman Major-General Waheed Arshad says the gunmen were fully prepared and mounted a strong resistance.

"They are very well armed and they are well trained," he said. "They have machine guns. They have rocket launchers. They have been using grenades. And secondly, there are women and children in the complex and we are taking a step-by-step approach to ensure there is no collateral damage unnecessarily."

The government says at least 70 women and children have been rescued and another 70 militants taken into custody.

Ambulances ferried scores of wounded to nearby hospitals, while the terrified parents of students trapped inside waited for the siege to end.

The bloody standoff began a week ago, after the mosque's radical students clashed with local security forces.

Pakistani paramilitary troops take position during heavy gunbattle with militants at Lal Masjid, or Red Mosque, 10 July 2007

Lal Masjid, or the Red Mosque, has been a well-known source of Islamic militancy and its supporters recently pushed to impose a strict Islamic law on the capital.

Their pro-Taleban cleric, Abdul Rashid Ghazi, said Sunday he and his supporters would rather die than surrender.

The military assault began an hour after government negotiators said they had failed to end the seven-day standoff. The militant leaders reportedly refused to give up a demand for complete amnesty and safe passage out of Islamabad.

Government officials say a number of foreign terrorists, including several with possible ties to al-Qaida, are inside the mosque.

There are mounting concerns the capital's unrest could spark a much wider militant backlash in other parts of the country.