Egypt Sinai: Dozens killed, wounded in mosque bomb attack
Suspected militants let off a bomb and opened fire at Al Rawdah mosque in Bir al-Abed, 40km west of Arish city in North Sinai.
The blast is thought to be one of the country's deadliest attacks in recent memory, state media reported.
The Islamic State group's 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.
They have also targeted followers of the mystical Sufi branch of Sunni Islam as well as Christians.
The victims included civilians and conscripts praying at the mosque.
A tribal leader and head of a Bedouin militia that fights IS told AFP that the mosque is known as a place of gathering for Sufis.
The Islamic State group shares the puritan Salafi view of Sufis as heretics for seeking the intercession of saints.
In recent times, attacks against security forces have also taken place in Egypt's western desert, where an ambush on Egyptian a police convoy led to the deaths of at least 16security personnel last month.
Militants operating in Egypt have maintained a steady war of attrition with sniper attacks, roadside bombings and attacks on civilian targets, including Coptic churches.
Unlike the IS group in Iraq and Syria, however, Islamist militants have been unable to seize population centres in Egypt.