The feud between Saudi Arabia and Iran sparked by Saudi Arabia's execution of a Shiite cleric shows no sign of abating.

After Saudi Arabia announced it was cutting diplomatic ties with Iran on Sunday, Bahrain and Sudan followed suit and severed their diplomatic relations with Iran.

The abrupt deterioration of ties between Saudi Arabia and Iran was triggered by Saudi Arabia's execution of 47 individuals it had convicted on terrorism charges, including a prominent Saudi Shiite cleric, Nimr al-Nimr.