Oman says the attacks on Saudi diplomatic posts in Iran are "unacceptable" but despite the criticism, it is not following other Gulf countries in limiting ties with Tehran.

Wednesday's remarks from Oman were its first over the ongoing tensions between Saudi Arabia and Iran, which began with the kingdom's execution of Shiite cleric Sheikh Nimr al-Nimr. Iranian protesters, angered by the execution, later attacked the Saudi Embassy in Tehran and a consulate in Mashhad.

Oman's Foreign Affairs Ministry says the sultanate felt "great sorrow" over the attacks and said it emphasized "the importance of establishing new norms (to) prohibit any form of interference in the internal affairs of other states in order to achieve stability and peace."

Oman is a long-time mediator between Iran and the rest of the world.