Egypt was last night reeling from the bloodiest terror attack in its history after suspected Isil fighters slaughtered at least 235 people during prayers by detonating explosives inside a Sinai mosque and then killing the worshippers in a hail of gunfire.

The terrorists struck a mosque in the remote town of Bir al-Abed in northern Sinai where hundreds of people had gathered for traditional Islamic prayers on Friday afternoon.

The attack began with a powerful explosion at the al-Rawdah mosque and gunmen leapt out of four off-road vehicles to kill people as they fled. Security officials and witnesses said the attackers used their vehicles to cut off escape routes and opened fire on ambulances as they reached the scene. More than 100 were wounded.

The gunmen appear to have escaped from the scene after the massacre before Egyptian security forces could arrive.

No group immediately claimed responsibility for the attack but suspicion fell on the Islamic State of Iraq and the Levant's (Isil) affiliate in the Sinai desert, which has waged a bloody insurgency against the Egyptian military and the country’s Christian minority.