ISLAMABAD, Pakistan  A powerful bomb struck the crowded alleyways of a central bazaar in the chaotic city of Peshawar on Friday, killing at least 29 people and wounding more than 90, Pakistani officials said.

The bomb exploded near the bazaar in Kissa Kahani, or Street of the Storytellers, at a time when the streets of Peshawar, in northwestern Pakistan, were crowded with people shopping for an approaching festival, the police said.

The chief of police in Peshawar, Malik Naveed Khan, told Pakistani television that the explosion, which took place about 7:20 p.m., struck near a Shiite mosque. He said he expected the numbers of dead and wounded to increase. A doctor said Saturday morning that several people had died overnight, raising the death toll to 29.

A loud explosion, which witnesses said blew out windows up to a half-mile away, was soon followed by fire, which engulfed scores of buildings in the narrow alleys nearby and severely hampered rescue efforts.