Suspected Al Qaeda suicide bombers carried out unprecedented strikes in Riyadh, Saudi Arabia, killing at least 29 people, seven of them Americans, and injuring 194, including nine Indians, hours before the arrival of US Secretary of State Colin Powell on Tuesday.

The dead also included nine suicide bombers who had shot their way into three compounds housing Westerners late Monday night.

A smaller bombing at a Saudi-US company followed the attacks.

A statement by the Saudi interior ministry said besides the bombers, the dead in the simultaneous attacks included seven Saudis, seven Americans, two Jordanian children, two Filipinos, a Lebanese and a Swiss.

The 35-year-old son of Riyadh's deputy governor, Abdullah al-Blaihed, was among those killed.

Earlier Powell, on his arrival in Riyadh, said, "Right now it seems as if we have lost 10 Americans and many other lives were lost from many other nationalities."

The Australian foreign affairs spokesperson in Canberra said a 39-year-old Sydney man who worked for a computer company died in the blast and another Australian was injured.