Blasts targetting foreigners' residential compounds in Riyadh overnight had "the earmarks of al-Qaeda", US Secretary of State Colin Powell today, condemning the explosions, which killed at least three people and wounded some 50.

"I think it's just part of al-Qaeda and other terrorist organisations' willingness to kill innocent people in order to push forward a criminal agenda, a terrorist agenda that very often has no purpose, has no meaning other than to strike out in rage," Powell said.

Asked who was behind the suicide attacks, Powell said, "I don't know yet, I think the suspects are clear though, it has the earmarks of al-Qaeda".

Saudi-born Osama bin Laden's terror group was responsible in particular for the September 11, 2001 attacks in the US.

Powell was speaking at a press conference in Amman during a Middle East tour, which is also scheduled to take him to Saudi Arabia.

"I condemn the terrorist attacks that took place in Saudi Arabia overnight, I condemn the cowardly individuals who sneaked in the middle of the night to kill innocent civilians," he also said.

"Terror is a global phenomenon which we must all fight". – Sapa.