The Daesh terrorist group has claimed responsibility for the deadly attack that killed nine Shia Muslims near a mosque in Oman on the Day of Ashura.

Daesh said in a statement late on Tuesday that three of its “assailants” fired on worshippers at the mosque in the Wadi Kabir district of the Omani capital city of Muscat on Monday evening, and exchanged gunfire with Omani security forces until morning.

The group also published what it said was a video of the attack on its Telegram channel.

Another video shared on social media and verified by Reuters news agency showed people running from the mosque while gunfire could be heard.

At least nine people, including four Pakistanis, an Indian and a police officer, were among those killed.

Royal Oman Police said at least 28 individuals, including four emergency service personnel, were also injured in the deadly shooting that occurred outside Imam Ali Mosque.

Police said investigations into the circumstances surrounding the shooting were underway but made no statement on the gunmen's motives.

Pakistan's ambassador to Oman said at least 50 Pakistani expatriate workers were injured in the incident.

He said at least 20 were being treated for bullet wounds in three hospitals in Muscat.

India's embassy in Muscat also said one Indian was killed and another injured in the attack.