Suicide bomber kills 20 in northwest Pakistan

The police station,a nearby mosque and a government office collapsed while portions of two other government buildings were damaged.

The bomber struck at 7 am,when most of the 45 policemen at the station were asleep following 8216;sehri8217;,the pre-dawn meal partaken ahead of a day-long fast during the Islamic holy month of Ramzan.

A school bus was passing the area when the blast occurred. A live electric wire fell on the vehicle,killing four children and injuring several others.

At least 10 policemen were among the injured. Several of the injured were in a critical condition,officials in local hospitals said.

Local residents joined rescue operations and rushed the injured to hospital in private vehicles.

The bomber targeted the police station from the rear as its front side and entrance were barricaded with cement blocks,officials said.

Experts of the bomb disposal squad said over 40 kilograms of explosives were used in the attack.

Officials said they feared the death toll could rise as rescuers were still clearing the rubble of collapsed buildings.

Police cordoned off the area and launched a search operation. No group claimed responsibility for the attack.

Lakki Marwat has witnessed several deadly terrorist attacks that targeted members of anti-Taliban militias and policemen.

In January,a Taliban bomber blew himself up at a football ground on the outskirts of the city and killed nearly 100 people. The people were targeted as they had resisted the Taliban8217;s efforts to infiltrate the area.