Saudi security forces found Islamic State group flags during a raid on Friday in which an officer was shot dead, the interior ministry said.
The killing came with the Gulf region on alert against attacks by IS, which has been blamed for killing other Saudi policemen and has claimed three deadly mosque bombings in the kingdom and Kuwait.
"They arrested three suspects, confiscated Daesh flags, silencers and personal laptops," the ministry said in a statement carried by the official Saudi Press Agency.
Daesh is an Arabic acronym for the Islamic State group.
