Sudan has decided to expel the Iranian ambassador in protest at an attack on Saudi Arabia's embassy in Tehran, Saudi state television station Ekhbariya reported on Monday.Saudi Arabia cut ties with regional rival Iran on Sunday after Iranian protesters attacked its mission there, angered by the kingdom's decision to execute a Shi'ite cleric.Sudanese officials could not immediately be reached for confirmation.The Gulf kingdom of Bahrain also severed diplomatic ties with Iran on Monday, hours after neighbouring Saudi Arabia broke off relations with Tehran.