A Shia mosque in an eastern province of Saudi Arabia has been reportedly attacked, Reuters said, citing local activists and social media.

The explosion allegedly took place near a Shiite shrine in Al-Ahsa province, some reports claimed.

Al Arabiya reported that at least three people were killed in the attack.

The blast was followed by gunfire at the Imam Rida Mosque in the town of Mahasen in al-Ahsa province, a local activist told Reuters.

(RT)