Gunmen have shot dead an American man in the Saudi capital Riyadh - the second such attack this week.
Saudi police are hunting gunmen after a spate of attacks
"We can confirm that an American has been killed in Riyadh," said a US embassy official quoted by the Associated Press news agency.
The shooting happened in al-Khalij district, in the east of the city - reportedly at the victim's home.
It came two days after gunmen attacked a BBC TV crew, killing a cameraman and seriously wounding a correspondent.
Police quoted by the official Saudi news agency SPA said they responded to a report of a shooting and found the American shot dead at his home.
One witness was quoted as saying the American had been followed home from a nearby clinic by two or three gunmen.
The victim, who has not yet been identified, was working for the US defence contractor Vinnell, a unit of Northrop Grumman Corp.
Vinnell is helping to train the Saudi National Guard - the monarchy's elite security force.
Seven Vinnell employees were among the 35 people killed last year in the bombing of a Riyadh
compound housing foreigners, AP reports. Nine suicide
bombers were also among the dead.
A company spokesman said the victim had chosen not to live in a protected compound alongside other Vinnell employees. His family was not with him in the kingdom, a neighbour said.
Meanwhile, BBC security correspondent Frank Gardner remains in intensive care in hospital after being shot by gunmen in the al-Suwaydi southern suburb of Riyadh on Sunday. Cameraman Simon Cumbers died at the scene.
Gardner's condition is improving but still critical, the BBC says.
Saudi security forces are hunting the gunmen who struck as the BBC crew filmed the house of an al-Qaeda militant in al-Suwaydi, a known stronghold of militants.
There has been a spate of increasingly brazen attacks on foreigners in Saudi Arabia, blamed on radical Islamists close to al-Qaeda.
In late May gunmen opened fire on foreigners in the eastern city of Khobar, killing 22 people.