DUBAI: The three gunmen who shot and killed six people at a Shia mosque in Oman in an attack claimed by Islamic State this week were all Omani nationals, police said on Thursday.

The assault began on Monday evening at the Ali bin Abi Talib mosque in the Wadi al-Kabir neighbourhood of Oman’s capital Muscat as Shia Muslims gathered.

The Royal Oman Police said the three gunmen were brothers and “were killed due to their insistence on resisting security personnel”. It said that police investigations had indicated the three gunmen were “influenced by misguided ideas”.

The six people killed by the gunmen were four Pakistani nationals, an Indian, and a police officer responding to the attack, which Islamic State later claimed responsibility for.

Pakistan has labelled the assault a terror attack.

Islamic State on Tuesday said that three of its “suicide attackers” fired on worshippers at the mosque on Monday evening and exchanged gunfire with Omani security forces until morning.

A video of what the Islamic State said were the three attackers behind the shooting was released on Thursday on the group’s Telegram channel.