Troops stormed the compound of Islamabad's Red Mosque on Tuesday, prompting a fierce firefight with militants accused of holding about 150 hostages inside, officials said.
"Troops have entered the madrassa" adjoining the mosque, army spokesman Gen. Waheed Arshad told The Associated Press. "There is intense firing going on."
He said 20 children had been rescued from the madrassa, or religious school, but had no word on any casualties.
The assault began minutes after a delegation led by a former prime minister left the area declaring that efforts to negotiate a peaceful end to the week-old siege had failed.