A suicide bomber on Tuesday blew himself up near a security check post in the cantonment area of the northwestern Pakistani city of Bannu, killing a policeman and a civilian and injuring five others.

The bomber, who detonated his explosives when police tried to stop him from getting near the check post, also died, officials said.

Witnesses said the attacker came to the check post in a cycle-rickshaw and wanted to enter inside but police foiled his attempt. He then blew himself up. A policeman and the rickshaw driver were killed in the blast.

Television channels put the death toll at three, including the bomber, though the district police chief confirmed only one policeman had died.

The injured were taken to the city's military hospital, where officials said some of them were in a critical condition. Among the injured were four policemen and a civilian.

Security forces cordoned off the area after the attack and did not allow reporters to go to the blast site.

The office of an intelligence agency, located a few hundred yards from the site of the blast, was the apparent target of the bomber, officials said.

The explosion occurred an hour before NWFP Governor Owais Ahmed Ghani's arrival in Bannu.

No group has claimed responsibility for the attack. Such attacks are usually blamed by authorities on pro-Taliban militants, who regularly target the Pakistani security forces, especially in the country's northwest.

Meanwhile, in a separate incident, two policemen were gunned down by militants in Matta town of Swat district on Tuesday.

The Pakistan Army had recently said that the writ of the government had been re-established in Matta.