The Imam at the largest Mosque in Ireland is calling on Irish Muslims to report any jihadist elements that may be operating here.

Doctor Ali Al-Saleh is Imam at the Miltown Cultural Centre in Dublin. He says it is his duty to speak out against ISIS sympathisers.

Last night, the US President Barack Obama announced that he has authorised air-strikes in Syria and Iraq as part of a campaign against the Islamic State militant group.

"We will hunt down terrorists who threaten our country, wherever they are," Mr Obama said. "That means I will not hesitate to take action against ISIL (IS) in Syria, as well as Iraq," Mr Obama said.

"This is a core principle of my presidency: If you threaten America, you will find no safe haven."

In the last few weeks, IS has released videos of its militants beheading kidnapped American journalists James Foley and Steven Sotloff.

Mr Obama also announced that he was sending around 500 more US troops to Iraq to assist its security forces and urged US Congress to authorise a programme to train and arm Syrian rebels who are fighting both the Islamic State militants and President Bashar al-Assad.

Dr Ali Al Saleh is asking Irish Muslims to cooperate with the gardaí in tackling ISIS here.