Four Irish citizens are among hundreds of people trapped in an Egyptian mosque that has been surrounded by security forces.

It's understood the group fear they will be attacked if they attempt to leave.

The three women and a teenager are children of Hussein Halawa - the Imam of Ireland's biggest mosque in Dublin.

The four siblings, who are on holiday in Egypt, are believed to have sought refuge in the mosque after 80 people were killed during violent clashes between supporters of ousted president Mohammed Morsi and the security forces in Cairo yesterday.

21 year old Omaima Halawa, 21 who is with her two sisters 27 year old Somaia and 23 year old Fatima as well as their 17 year old brother Ibrihim has described the scene in Cairo as very frightening.

Speaking to Al Jazeera News from inside the Mosque, Omaima said they had been warned they could be shot if they tried to leave and that security forces had already entered the building.

The Department of Foreign Affairs say they have been in contact witha a group of Irish people but could not confirm how many or if they were related.

The four had travelled to Egypt with their mother for a holiday earlier this summer - while their father remained in Dublin.

From the family home at Firhouse in the south of the city, another sister Nasaybi said they were enduring a terrible ordeal.

Meanwhile, the Irish Anti-War Movement is calling on the Irish government to for sanctions against Egypt over the violence.

60 people were killed during clashes yesterday as supporters of the ousted president Mohamed Morsi took to the streets to demonstrate over the killing of more than 600 people earlier this week.

A protest is being held outside the Egyptian Embassy in Ballsbridge in Dublin at 2 o'clock this afternoon, to condemn the massacre.