A statement by the Riyadh police carried by the official Saudi Press Agency today said an attacker armed with an assault rifle seized the workers yesterday evening near a mosque and opened fire when surrounded by police.
He was eventually wounded and captured.
Police say the hostages were freed. In addition to the slain officer, a civilian and a member of the security forces were injured.
The incident comes amid growing concerns about militant attacks in the kingdom in retaliation for its role in the coalition battling the Islamic State group.