Pakistani officials say at least nine people, including the bomber, have been killed in a suicide attack outside the office of a top police chief in northwestern Pakistan.

They say at least five police officers and three civilians were among those killed in Friday's attack in the town of Mardan.  More than 25 people were wounded.

Mardan's police chief Akhtar Ali Shah told reporters he heard an explosion outside his office as he was about to leave.  The blast took place close to members of the police chief's convoy.  He was not hurt.

No group has claimed responsibility for the attack.

Mardan is near the area where Pakistani forces have been battling Taliban and al-Qaida militants for months.

On Thursday, Pakistani security officials say they detained a suspected Taliban commander and killed at least five other militants during an operation in the Mohmand tribal region bordering Bajaur.

They say the commander helped prepare suicide bomb materials and maintained links with insurgents across the border in Afghanistan.