Riyadh - Saudi police have safely dismantled an explosive charge on an American's car in Riyadh and a suspicious object has been found on a Briton's vehicle, the British embassy said on Sunday.

The incidents on Saturday and Sunday came less than two weeks after a car bomb killed a British banker in the Saudi capital.

The embassy notice, published on its website, said the object had been found on the Briton's car near his home at the Al Nakheel residential compound in central Riyadh on Sunday.

It said Saudi authorities "have not confirmed that the object was an explosive device", adding that an investigation was under way.

Saudi police dismantled an explosive device that had been discovered on Saturday on the vehicle of a US citizen resident in Riyadh, the embassy statement said.

US and Saudi officials were not immediately available to comment on the reports.

"The incidents underlined the importance of checking vehicles thoroughly before entering them," the British statement said.

Western residents of the oil-rich kingdom, a key Gulf Arab ally of the United States, have been anxious since the June 20 explosion that killed British banker Simon John Veness, who worked at Al Bank Al Saudi Al Fransi in Riyadh.

The explosion, which is still under investigation, also occurred near Al Nakheel compound.

Saudi authorities said earlier this month they had arrested seven members of Osama bin Laden's al-Qaeda network on suspicion of planning "terrorist" attacks on vital installations in the country.

Washington blames Saudi-born dissident Bin Laden and al-Qaeda for the September 11 attacks on New York and Washington.

About 30 000 Britons and 40 000 Americans live and work in Saudi Arabia.