Saudi forces say they have arrested a wanted terrorist and several other people, following a bloody firefight in which six people were killed. But they have not provided the name of the main suspect.
Saudi security forces say they received information about weapons and explosives at the residence of a man wanted on security charges.
The tip led them to a house in eastern Riyadh, where a security unit found grenades, pistols and automatic rifles.
The Saudi forces came under fire as they were completing the raid. At least five security agents and the prime suspect's father were killed.
Saudi officials say they apprehended the main suspect and several others.
The arrests were made about 700 kilometers from Mecca, where millions of Muslims plan to embark on the annual pilgrimage, or Hajj, on Friday.