One policeman was killed and three others wounded in clashes with militants in a town northeast of Riyadh, a Saudi Interior Ministry official said Friday.

The unidentified official, quoted by the official Saudi Press Agency, also said a number of suspects in Thursday's shooting were arrested.

Two police patrols checking a report that armed suspects were in a house in al-Baradah, 250 miles northeast of Riyadh, were fired on by suspects in a vehicle as they approached the house, the official said, adding that a later search of the house revealed large amounts of explosives and weapons. No more details were available.

Al-Arabiya TV reported Friday that one of the three wounded police officers was in critical condition.

Thursday's clashes came a day after the surrender of a wanted militant identified by Saudi authorities as Abdullah bin Abdul Aziz al-Moqrin (search). Al-Moqrin was accused in a May attack in the eastern city of Khobar that killed 22 people, most of them foreign oil industry workers.

He is believed to be related to Abdul Aziz al-Moqrin, believed to have been Al Qaeda's chief in Saudi Arabia when he was killed in June.

The region has been a site of frequent attacks linked to Al Qaeda (search ) in Saudi Arabia. In April, four security officers were killed when a group of militants opened fire on a checkpoint in the region.

Saudi Arabia offered a monthlong amnesty that expired in July to encourage wanted militants to surrender, pledging not to seek the death penalty against them if they do so. Four men surrendered to Saudi authorities under the amnesty, but none was on the list of 26 most-wanted militants that authorities issued in December.

Since May 2003, suspected Islamic militants have carried out numerous suicide bombings and kidnappings, and have engaged regularly in gunbattles with security forces. The attacks, which have tended to target foreign workers, have been blamed on the Al Qaeda terror group and its allies.