The army’s announcement did not say when the operation took place but named the head of the Egyptian affiliate of the jihadist group based in the Sinai Peninsula as Abu Doaa al-Ansari.

He was killed along with top aides and dozens of others jihadists in an operation carried out jointly by the air force and the anti-terrorism squad, the army’s spokesman said on Facebook.

Since Egypt’s military overthrew Islamist president Mohamed Morsi in 2013, jihadists have spearheaded an insurgency against the army and police with daily attacks in North Sinai.

Most of the attacks that have killed hundreds of policemen and soldiers have been claimed by the “Sinai Province”, the Egyptian branch of IS.

Military forces “were able to kill the leader Ansar Beit al-Maqdis, the terrorist called Abu Doaa al-Ansari, and a number of his top aides in addition to more than 45 terrorist elements,” said the spokesman.

A military source told AFP that Ansari was the group’s “number one” leader.

Ansar Beit al-Maqdis was the previous name of the jihadists before the group swore allegiance to the Islamic State group in November 2014.

The statement said dozens of others were “targeted with precise hits” in the operation against strongholds of the group south and southwest of the Sinai city of El-Arish.

The operation destroyed depots where weapons, ammunition and explosives were stashed, it added.

– Trail of deadly attacks –

The military has poured troops and armour into the peninsula where security forces have been battling a jihadist insurgency since then army chief and now President Abdel Fattah al-Sisi ousted Morsi more than three years ago.

But the jihadists have remained defiant and kept up attacks mostly against the security forces using roadside bombs and ambushes.

They have also targeted Egyptian Christians and claimed attacks on foreigners and diplomatic missions, including last year’s attack on the Italian consulate in Cairo

In 2015 they the group also claimed to have beheaded a Croatian man who worked for French geoscience company CGG, after abducting him on a road running from the west of Cairo.

Later that year the interior ministry announced the killing of top IS operative Ashraf Ali Hassanein al-Gharabli suspected of involvement in the abduction and murder of the Croatian and the bombing of the Italian consulate.

In another of its worst attacks, the group claimed responsibility for bombing a Russian airliner carrying holidaymakers from an Egyptian resort last year, killing all 224 people on board.

The group said it had smuggled a bomb on board at an airport in the south of the peninsula.

The army has regularly announced the death or capture of jihadists, who have often claimed their attacks were in retaliation for a police crackdown that has killed hundreds and left thousands in jail since Morsi’s ouster.

The arid and rugged Sinai Peninsula borders Israel and the Palestinian Gaza Strip.

El-Arish is the provincial capital of North Sinai where the jihadists are active.