A suicide bomber set off an explosion during weekly prayers in a Shiite mosque of eastern Saudi Arabia leaving many dead Friday, the interior ministry said.

"It has been established that an individual detonated a bomb he was wearing under his clothes during Friday prayers at Ali Ibn Abi Taleb mosque in Kudeih in Qatif province," the interior ministry spokesman said.

The spokesman, in a statement carried by the official SPA news agency, said the attack left many dead and wounded, without giving a specific toll.