TEHRAN (Press Shia) – Militants killed 235 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 insurgency. No group claimed immediate responsibility, but since 2014 Egyptian security forces have battled a stubborn Daesh (ISIL or ISIS) affiliate in the north of the mainly desert Sinai, where militants have killed hundreds of police and soldiers.

State media showed images of bloodied victims and bodies covered in blankets inside the Al Rawdah mosque in Bir al-Abed, west of the city of El Arish.

State television and the official news agency MENA reported that 235 people had been killed. Scores more were wounded, according to state media.

"They were shooting at people as they left the mosque," a local resident whose relatives were at the scene told Reuters. "They were shooting at the ambulances too."

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

President Abdel Fattah el-Sisi, a former armed forces commander who presents himself as a bulwark against militants, convened an emergency meeting with his defense 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.

In July this year, at least 23 soldiers were killed when suicide car bombs hit two military checkpoints in the Sinai, an attack claimed by ISIS.

Militants have tried to expand beyond the largely barren, Sinai Peninsula into Egypt's heavily populated mainland, hitting Coptic Christian churches and pilgrims.

In May, gunmen attacked a Coptic group travelling to a monastery in southern Egypt, killing 29.