Osama bin Laden personally ordered the recent suicide bombings in the Saudi Arabian capital of Riyadh, which killed 34 people and injured many, NBC-TV reported quoting US intelligence and counter-terrorism officials.

Claiming that bin Laden was alive, the channel quoted its sources saying that half a dozen other countries, including Malaysia, Indonesia, Liberia, Somalia and Kenya, are likely targets next.

On Thursday, US President George W Bush vowed to hunt down those responsible for Monday night's bombings.

FBI Director Robert Mueller said he was sending a team of agents to help Saudi authorities with the investigations.