The blast left a deep crater in the street, and was large enough to shatter windows in shops hundreds of metres away. It also caused extensive damage to the Islamic antiquities museum across the street.

Witnesses said they heard gunshots before the explosion. “It was around 7am this morning. I heard shots and then the ground shook, the windows shattered,” said Mohamed Taher, sweeping broken glass outside his cafe near the bomb site.

The bombing bore many of the hallmarks of Ansar Bait al-Maqdis, a Sinai-based armed group that has carried out numerous high-profile attacks over the past year, most recently a December 24 bombing outside a police station in Mansoura that killed 14 people.

The group released an audio message on Thursday night, hours before the bombing, that threatened further attacks on police and army targets.