A U.S. national was shot dead and another was wounded Tuesday when their car was fired upon in Saudi Arabia’s capital of Riyadh, the State Department confirmed.

"We can confirm that two U.S. citizen employees from Vinnell Arabia, a U.S. defense contractor supporting Saudi National Guard military programs in Riyadh, were shot at a local gas station/store approximately .5 miles from the Vinnell Arabia base in Riyadh, which is located approximately 20 miles from the U.S. Embassy," spokeswoman Jen Psaki said in a statement Tuesday afternoon.

The other employee was "lightly injured," the State Department said.

"The attack resulted in the killing of one person and wounding [of] another and it turned out they were of American citizenship," according to a police statement carried by state media.

The attacker was cornered and arrested, the statement said. He was injured by police gunfire, a Saudi Interior Ministry source told Fox News, citing accounts from witnesses.

The Saudi Interior Ministry identified the attacker as Abdulaziz Fahad Abdulaziz Alrashid.

The Saudi Embassy in Washington D.C. told Fox News that Alrashid is a 24-year-old American-born Saudi who worked at the same company as the victims. He had been let go from his job over drug-related issues.

"We are in close contact with the Saudi government as we continue to gather details about the shooting and motive," the State Department statement said. "We are in the process of evaluating our security posture and will take appropriate steps to ensure the safety of all U.S. Mission personnel."

Psaki said the U.S. Embassy is issuing a security message to U.S. citizens to advise them of any safety precautions they should take.

The last time Westerners were killed in Saudi Arabia was in 2007, when three French nationals were shot dead while camping, Reuters reports.

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Fox News’ Amy Kellogg contributed to this report.