Iran sent a letter on Monday to the UN Security Council expressing its “regret” over attacks by protesters on Saudi missions in the Islamic republic, vowing to prevent any similar incidents in the future. “The Islamic Republic of Iran expresses its regret over the referred-to incidents and will spare no efforts in arresting and prosecuting all those who brought them about,” said the letter dated Monday. It added: “The Islamic Republic of Iran will take necessary measures to prevent the occurrence of similar incidents in the future.” Saudi Arabia on Sunday officially severed its ties with Iran, with Bahrain following in its footsteps a day after. The kingdom announced later that it would also cut commercial ties, including flights and travel of Saudi citizens to the Islamic Republic. Riyadh cut its ties after two of its diplomatic posts were attacked in the capital Tehran and the northeastern city of Mashhad, accusing Tehran of not doing enough to stop protesters from damaging its premises. However, Iran said in the letter that Tehran took “necessary measures, including the increase in the number of security forces, to prevent any assault against the premises of the Consulate.” The letter said that around 8,000 “peaceful protesters” had stood in front of the Saudi embassy in the Iranian capital but some of them “at around 11:00 p.m.” got out of control. “Despite the extensive efforts made by the law enforcement authorities, some of them managed to enter the embassy and inflict some damages on the building,” it added, according to Saudi Gazette.