A suicide bomber has struck a police patrol in a town in northwestern Pakistan, killing a policeman and wounding six others, police have said.

The bombing took place at a market in Katalang, 50km northeast of Peshawar, the capital of restive Khyber Pakhtunkhwa province which borders Afghanistan.

"A policeman was killed and two other policemen were wounded when a suicide bomber blew himself up close to a police patrol car," senior police official Shafi Ullah told AFP news agency.

Four civilians were also wounded in the bombing, Ullah said.

After the attack police chased an alleged accomplice and killed him in a shoot out, the official said.

Two other police officials confirmed the account and casualties.

Nobody has claimed responsibility for the attack, but Taliban gunmen in the past have carried out several bombings in the region.

Separately, a bomb blast damaged a non-governmental organisation office in Peshawar early on Saturday but caused no casualties, police said.

The bomb exploded outside the office of Sawera, an NGO working for women rights and voters' education, at 4:00am local time (23:00 GMT) in the upmarket area of Hayatabad, senior police official Faisal Murad told AFP.

An official at Sawera said the organisation had not received any specific threat but armed gunmen have attacked NGOs and aid workers in the past.

Pakistan says more than 35,000 people have been killed as a result of terrorism in the country since the 9/11 attacks on the United States.

Source: Agencies