Militants killed 184 people at a mosque in Egypt’s north Sinai region on Friday, detonating a bomb and shooting at fleeing worshippers and ambulances, state media and witnesses said.

It was one of the deadliest attacks in the region’s Islamist insurgency. No group claimed immediate responsibility, but since 2014 Egyptian security forces have battled a stubborn Islamic State affiliate in the north of the mainly desert Sinai, where militants have killed hundreds of police and soldiers.

State television and the official news agency MENA reported that 184 people had been killed. Another 125 were wounded, according to state media.

Arabiya news channel and some local sources said some of the worshippers were sufis who hardliners such as Islamic State regard as apostates because they revere saints and shrines, which for Islamists is tantamount to idolatry.

President Abdel Fattah al-Sisi, a former armed forces commander who presents himself as a bulwark against Islamist militants, convened an emergency meeting with his defence and interior ministers and intelligence chief soon after the attack, the presidency’s Facebook page and state television said.

The government also declared three days of mourning.

Militants have mostly targeted security forces in their attacks since bloodshed in the Sinai worsened after 2013 when Sisi, then an armed forces commander, led the overthrow of President Mohamed Mursi of the Muslim Brotherhood.

But jihadists have also targeted local Sinai tribes that are working with the armed forces, branding them traitors for cooperating with the army and police.