The blast brought down buildings in the northwestern city of Peshawar just hours after US Secretary Hillary Clinton arrived in Pakistan to bolster the two countries' alliance against Taliban and Al-Qaeda militants.

Many of the casualties were women and children said doctors at the Lady Reading Hospital.

"We have 92 dead and 217 wounded. Nineteen of the dead are women and 11 are children. All the dead are civilians," Doctor Zafar Iqbal told AFP as staff declared an emergency and called for blood donations.

Peshawar is home to 2.5 million people and a gateway to the tribal badlands where the military is mounting a massive offensive against the Taliban in its toughest battle so far.

AFP