(By Bonny Apunyu)

At least 21 people were killed and 81 wounded in an attack by an Islamic State group suicide bomber on a Shiite mosque in Saudi Arabia on Friday, the health ministry said, AFP reported Saturday.

According to Saudi Arabia's news agency APS, "the terrorist attack left 21 dead and 81 wounded, including 12 in critical condition", the ministry reportedly said.

Reports say the bomber struck during the main weekly prayers in Eastern Province, where assailants linked to the Sunni extremist IS killed seven members of the minority Shiite community in November.