RIYADH, Sept 5: Three Saudi security officers were killed on Sunday when their patrol car caught fire after being hit by gunfire while chasing suspected extremists in an area considered a militant haven, a security source said.

"A patrol car caught fire after it was hit by a bullet while chasing a suspects' car, which led to the martyrdom of three security men," in Buraidah, 340 kilometres northwest of Riyadh, the security source said.

Seven suspected extremists were also earlier arrested in a dawn sweep by security forces of southern neighbourhoods of Buraidah in the Al-Qassim region, he added. He said the identities of the suspects were being checked, but did not give any further details on the operation.

The killings of the security officers was the third violent incident to take place in as many days in the area. Security forces killed a suspected militant and arrested another on Friday in a similar car chase, hours after a security officer was shot dead and three others wounded when their patrol car came under fire.

Security forces have repeatedly clashed with suspected Al Qaeda militants blamed for a wave of violence in Saudi Arabia since May 2003. Many have been killed in the gun battles. -AFP