At least 235 people were killed and another 109 injured in an attack on a mosque in Egypt's North Sinai region on Friday, Egyptian state-run Nile TV reported, making it one of the deadliest attacks ever carried out against civilians in the province.
Egyptian President Abdul Fattah al-Sisi has held emergency talks with security officials to decide how to respond.
Local police said gunmen arrived in four off-road vehicles before opening fire on worshippers, AP reported.
Locals are also quoted as saying that followers of Sufism, or Islamic mysticism, regularly gathered at the mosque.
Some jihadist groups, including so-called Islamic State (IS), see Sufis as heretics.