RIYADH, Saudi Arabia — An American citizen was fatally shot in the Saudi capital yesterday, a U.S. Embassy official said, the second deadly shooting of a Westerner in the kingdom in three days.

“We can confirm that an American has been killed in Riyadh,” a U.S. Embassy official said, but provided no further details.

Police responding to a report of a shooting found the American fatally shot in his home in the Khaleej neighborhood in eastern Riyadh, the official Saudi news agency said. The death was under investigation, it said.

The victim worked for Vinnell Corp., a U.S. defense contractor based in Fairfax, the official said. Seven Vinnell employees were among the 35 persons, including nine suicide bombers, who died last year in an attack on a Riyadh foreigners’ housing compound.

Vinnell, which has several dozen Americans in the kingdom training Saudi security forces, maintains a secure residential compound for its employees, but the victim chose not to live there, spokesman Jay McCaffrey said.

Besides training security forces, Vinnell Corp., a subsidiary of Northrop Grumman Corp., also provides other services, ranging from construction to supply and transportation work. Last year, it was awarded a $48 million contract to train the new Iraqi army.

Saudi officials have blamed a string of attacks on Westerners, government targets and economic interests in the kingdom on militants inspired by or belonging to al Qaeda, the anti-Western terror network led by Saudi-born Osama bin Laden.

An Irish cameraman and a British reporter for the British Broadcasting Corp. came under fire Sunday while filming a militant’s family home in Riyadh. The cameraman, Simon Cumbers, 36, was killed, and BBC security correspondent Frank Gardner, 42, was critically injured.

The British Foreign Office has advised Britons against all nonessential travel to Saudi Arabia. The United States has gone further, urging all of its citizens to leave.

There has been an upsurge of violence in the kingdom despite a high-profile antiterror campaign that the government began last year after attacks on residential compounds.

A 25-hour shooting rampage and hostage-taking that began May 29 killed 22 persons, most of them foreigners, in the eastern Saudi oil hub of Khobar. Saudi security forces captured one of the four attackers in that assault and are still looking for the other three.

On May 22, a German chef was shot and killed outside a bank in Riyadh. The assailants remain at large.

On May 1, a terrorist attack targeted the offices of an American energy company in the western city of Yanbu, killing six Westerners and a Saudi.