RIYADH (AFP) - Gunmen shot dead a British man in the Saudi capital Riyadh, the latest in a spate of attacks on Western expatriates in the oil-rich kingdom.

Security sources named the victim as Edward Smith, 50, and said he worked for Marconi telecommunications corporation, which provides consultancy services to the Saudi National Guard.

A security source told AFP Smith was fatally shot in the parking lot of a commercial establishment in the eastern sector of the city.

Witnesses said the victim was gunned down outside a supermarket on Khraiss road at around 5:00 pm (1400 GMT). They said two gunmen shot him with four bullets as he headed towards his car.

The attackers, who were in a car, sped away, the witnesses said.

Interior ministry spokesman Mansur al-Turki confirmed to AFP that two men were involved in the attack, using one pistol. He said the assailants had apparently been following the victim, as they were waiting for him in the car park.

"Two men got out of a car and shot the victim before getting in the same car and running away," he added.

The British embassy here later confirmed the Briton`s death without giving his name.

An embassy statement said the killing had strengthened the British government`s determination to support Saudi Arabia and its people in their fight against terrorism.

The motives of the killing were not immediately known, but suspected Al-Qaeda extremists have been blamed for a string of attacks on Westerners in Saudi Arabia.

The last fatal attack was on August 3, when an Irish engineer was shot dead in Riyadh.

A US diplomatic car came under fire in the Red Sea city of Jeddah on August 30, but no one was hurt.

The Irishman`s death, later claimed by the Saudi branch of the Al-Qaeda network, shattered a lull that had followed the June 18 killing of the local Al-Qaeda commander.

Saudi security forces shot dead Abdul Aziz al-Muqrin, head of "Al-Qaeda in the Arabian peninsula", and three associates in Riyadh shortly after their group had publicized pictures of the beheading of American engineer Paul Johnson, who had been abducted in the capital.

The targeting of Westerners began in May, a year after suspected Islamist militants launched a wave of bombings in the Saudi capital.

Six Westerners were killed when gunmen went on a shooting spree at a petrochemical plant in the Red Sea industrial port of Yanbu on May 1.

An Irish cameraman was shot dead and a British BBC journalist critically wounded in an attack in the Saudi capital on June 6, just a week after a shooting and hostage-taking rampage in the eastern oil city of Al-Khobar left 22 people dead, including four Westerners.

On May 22, a German national was shot dead outside a bank in Riyadh, and on June 2, an American serviceman who helps train the Saudi National Guard was slightly injured in another shooting outside the capital.

Two more US citizens were shot dead in Riyadh on June 8 and 12. In the June 8 incident, the American, who worked for Vinnell Corp., which also helps train the National Guard, was shot dead in his home and video footage of the murder was posted on an Islamist website.

Britain has since February urged its citizens to stay away from Saudi Arabia and advised those living here, who number between 25,000 and 30,000, to take stringent security precautions.

Two Britons were among the victims of the Yanbu shootings and a third died in the May 29-30 attack in Al-Khobar.

Following Muqrin`s elimination, King Fahd offered an amnesty to suspected Al-Qaeda extremists who turned themselves in within a month, portraying it as a last chance for members of the "deviant group" to mend their ways or face a merciless crackdown.

But only six militants gave themselves up, and just one figured on a list of 26 most-wanted extremists. Eleven of them remain at large.

Saudi authorities, who have rounded up hundreds of suspects since the violence erupted, have since again vowed to crush the extremists who spurned the pardon offer.

More than 90 people have been killed and hundreds have been wounded in the shootings and bombings of the past 16 months.