Militants killed more than 230 people at a mosque in North Sinai on Friday, detonating a bomb and gunning down worshippers in the deadliest such attack in Egypt’s modern history, state media and witnesses said.

No group immediately claimed responsibility, but since 2013 Egyptian security forces have battled an Islamic State affiliate in the mainly desert region, and 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 El Arish, the main city in North Sinai.

Worshippers were finishing Friday prayers at the mosque when a bomb exploded, witnesses said. Around 40 gunmen set up positions outside the mosque with jeeps and opened fire from different directions as people tried to escape.

”Four groups of armed men attacked the worshippers inside the mosque after Friday noon prayers. Two groups were firing at ambulances to deter them, said Mohamed, a witness.

The public prosecutors’ office said in a statement 235 people had been killed and 109 more wounded.