PESHAWAR, Pakistan - A roadside bomb packed with steel pellets exploded in Pakistan's violence-plagued northwestern city of Peshawar on Thursday, wounding two policemen and an 11-year-old girl, officials said.

The remote-controlled device was planted near a power pylon in a congested area and targeted a police station chief, police official Hayatullah Khan said.

"The official, Riazul Islam, accompanied by his police guard, was driving to his office in his private car when the bomb went off," Khan said.

An 11-year-old girl, the official and his guard were wounded, Khan said. Witnesses said the car was damaged and its wind shield smashed.

Doctor Zafar Iqbal of Peshawar's main Lady Reading Hospital confirmed the casualties but said they were out of danger.

"The bomb, wrapped in a packet, carried about two kilogrammes (four pounds) of explosives and was fitted with steel pellets to inflict maximum injuries," bomb squad official Tanvir Ahmed told AFP.

Militant bomb attacks have surged in Peshawar as Pakistan troops operate against the Taliban in the surrounding tribal belt, including a major air and ground offensive designed to flush out their stronghold in South Waziristan.

The sprawling city of 2.5 million people lies on the edge of Pakistan's lawless tribal belt, which US officials call the most dangerous place on Earth and where Al-Qaeda militants are plotting against the West.

Around 30,000 Pakistani troops have been fighting for nearly seven weeks in Taliban strongholds in the hostile terrain near the border with Afghanistan, where 100,000 NATO and US troops are fighting a deadly insurgency.