EL-ARISH, Egypt (CBS) Militants attacked worshippers at a mosque in Egypt killing at least 200 people.
There was confusion and panic outside the mosque after Egypt's deadliest ever terror attack. Worshippers were praying when militants detonated a powerful bomb. As people ran, they were gunned down by attackers in off-road vehicles parked outside. Gunmen also targeted ambulances which had arrived to treat the injured.
The terrorists blew up parked cars to block escape routes.
The attack happened in the North Sinai region, where the Egyptian government has been fighting Islamic insurgents.
Egypt's president promised a brutal response and declared three days of mourning.
No group has claimed responsibility but authorities believe an Islamic State affiliate may have been behind the massacre.
President Trump called the terrorist attack horrible and cowardly. He tweeted, "The world cannot tolerate terrorism, we must defeat them militarily and discredit the extremist ideology that forms the basis of their existence!"