Islamic State, a Sunni Muslim-dominated group, has claimed responsibility for an attack on a Shia Muslim mosque in Oman that killed at least nine people, including three of the attackers, in a rare incident in this Persian Gulf country.

The Islamic State said in a statement that three "suicide bombers" targeted worshipers at the mosque on Monday evening and exchanged fire with Omani security forces until the morning. The group also published what it said was a video of the attack on its Telegram website.

Four Pakistanis, an Indian and a policeman were among those killed in the gun attack, Pakistani, Indian and Omani officials said. Omani police said 28 people of different nationalities were injured, including security personnel.

The attack began Monday evening at the Ali bin Abi Talib mosque in the Wadi al-Kabir area of the Omani capital Muscat, 500 meters from the international school and an adjacent skate park, authorities said.

Such violence is exceptional in the wealthy Gulf countries dominated by Sunni Muslims, raising fears that the Islamic State, which has operated undercover since it was largely defeated by a US-led coalition in 2017, might try to come back.