Nine people were killed, including three attackers, and more than two dozen others were injured in an assault on a Shi’ite Muslim mosque in Oman late on Monday, law enforcement said, in a rare security breach in the oil producing Gulf state, Report informs via Reuters.

Four Pakistanis, an Indian and a police officer were among those killed in the gun attack, according to Pakistani, Indian and Omani officials.

The Oman police said 28 people of various nationalities were wounded, including security personnel.

Police have not said whether they have identified a motive for the attack or if they had made any arrests. The identity of the attackers has also not been released.