One policeman has been killed and up to 20 other people wounded in an explosion outside police headquarters in the east Yemen town of Sayun.

Witnesses and medics described Friday's blast as being carried out by a suicide bomber driving a booby-trapped vehicle.

The driver of the vehicle was also killed in the explosion.

Other witnesses said the blast sparked fires at the entrance to the police headquarters and neighbouring buildings.

No group has claimed it carried out the attack.

Hospital sources said the 20 wounded included both police and civilians.

Sayun, in the heart of Hadramut province, is 700km east of the capital, Sanaa.

The Yemeni authorities have not yet commented on Friday's blast.

There have been several recent attacks in the country attributed to or claimed by the al-Qaeda network.