A car bomb outside a police station killed at least three people and wounded 15 in Mardan town in northwest Pakistan on Friday, a senior police officer said.

"The car was parked outside the police station. It was packed with explosives and blew up, damaging the station and several nearby shops in the bazaar," senior officer Tahir Khan said.

He said a police officer was among the dead.

The blast broke a lull in Islamist militant attacks on security forces that had held since a new government came to power at the end of March.

The new government, made up of coalition partners opposed to President Pervez Musharraf, has pledged to try to use negotiations to halt the violence that has claimed well over a 1,000 lives since mid-2007.

The government has said it was talking with elders of ethnic Pashtun tribes that inhabit the rugged northwest, not directly with militant commanders.

With talks under way, Baitullah Mehsud, a militant leader accused by the previous government of organising the assassination of former Prime Minister Benazir Bhutto in December, earlier this week ordered his followers to cease attacks in Pakistan.

Based in the restive semi-autonomous tribal region of South Waziristan, Mehsud is the leader of the Pakistani Taliban, and is regarded as having strong links to al Qaeda fighters hiding on the Pakistan-Afghanistan border.

Leaders of Bhutto's party, which leads the new coalition, are doubtful over whether Mehsud was responsible for their leader's assassination and want the United Nations to investigate the killing.