A US national was shot dead and another wounded in Saudi Arabia's capital Riyadh Tuesday, the Saudi Press Agency reported.
The two Americans were shot in a petrol station on the east side of Riyadh, the report said.
Police later arrested the attacker. The assailant's identity has not been revealed yet, as an investigation is still underway.
It is the first killing of a westerner in the kingdom since 2007 when armed assailants shot dead three French nationals who were camping in the northwest of the country. The suspected perpetrators were suspected to belong to the Al Qaeda and are on trial in Riyadh.
Al Qaeda has carried out a series of attacks against foreign and government targets in Saudi Arabia from 2003 to 2006, killing hundreds before being crushed by the country's security forces.