Egyptian security forces have killed 98 militants in Sinai during a recent military operation, the military said on Friday.

Egypt is battling an insurgency that gained pace after the overthrow of President Mohamed Morsi of the Muslim Brotherhood Islamist movement in mid-2013 after mass protests against his rule.

The insurgency, mounted by Islamic State's Egyptian affiliate, has killed hundreds of soldiers and police and has started to attack Western targets. In the latest fighting, four Egyptian soldiers were killed, the military said.

President Abdel Fattah El-Sisi describes Islamist militancy as an existential threat to Egypt, the most populous Arab state.

Islamic State group controls large parts of Iraq and Syria, has a presence in Libya and enjoys the support of militants in Egypt.

*The story was edited by Ahram Online.