A suicide bomber blew himself up in Peshawar on Wednesday, killing at least six people including a senior police officer, officials said.

The blast ripped through a congested part of the city, which lies close to tribal areas and is frequently hit by bombings, leaving blood and body parts in the street.

Police official Badshah Khan said the bomber, who was on foot, targeted the vehicle of senior investigator Hilal Haider, killing him and a number of his colleagues.

Another officer, Asif Iqbal, told AFP there were six dead including four policemen.

Hospital officials and senior administration official Habibullah Arif said more than 30 people were wounded and some were in critical condition.

Witness Amin Khan described the moment the bomber struck.

"I was in a rickshaw, going to the local market to purchase tea for my shop," he said.

"Suddenly a deafening blast shook the area. My rickshaw was overturned. When I came out I saw smoke and dust had covered the blast site," he said.

President Asif Ali Zardari and Prime Minister Pervez Ashraf have strongly condemned the explosion.

They said such cowardly acts will not weaken the government's resolve to root out terrorism in the country.

Interior Minister Rehman Malik has sought a report from IG Khyber Pakhtunkhwa police on the explosion.

Khyber Pakhtunkhwa Governor Masud Kausar while condemning the explosion‚ paid great homage to police officers and jawans for their unprecedented sacrifices in the war on terrorism.