Armed assailants killed at least 115 people in an attack on a mosque in Egypt's volatile northern Sinai Peninsula during Friday prayers, MENA state news agency said, citing an official source.
At least 80 more people were wounded in the attack that targeted worshipers near the Sinai capital of el-Arish, the report said.
According to the Egyptian health ministry, there was a high death toll because the militants targeted the ambulances transporting victims of the attack on al-Rawdah mosque in the town of Bir al-Abd, 40 km from el-Arish.
Earlier, officials said militants in four off-road vehicles bombed the mosque and fired on worshipers during the sermon segment of the prayers.
ISIS' Egypt branch has killed hundreds of policemen and soldiers, and also civilians accused of working with the authorities, in attacks in the north of the Sinai peninsula.
The victims of Friday's attack included civilians and conscripts praying at the mosque.
Egypt's government declared three days of mourning after the attack.