At least three people have been killed in an attack on a mosque in al-Ahsa, eastern Saudi Arabia, according to a report by the Al Arabiya news organisation.
An activist, citing witnesses, separately told the Reuters news agency earlier on Friday that an explosion was followed by a gun attack on Imam Rida Mosque in the town of Mahasen in al-Ahsa region in the Eastern Province.
Residents said security forces were exchanging gunfire with five "terrorists".
Security officials told the Associated Press news agency that the three dead was an initial toll. They spoke on condition of anonymity as a formal announcement had yet to be made.
Witness Mohammed al-Nimr told The Associated Press that security forces and ambulances quickly surrounded the mosque. He said that it was a shooting and that worshippers stopped the attacker from detonating a suicide bomb belt.
No one has yet claimed responsibility for the attack.



ALJAZEERA
YEMI