At least four Egyptian soldiers have been killed in a shelling attack carried out by militants in Egypt’s Sinai Peninsula.

Egyptian sources said the incident took place on Tuesday in the peninsula’s northern region.

Meanwhile, the Egyptian army has killed more than 50 militants linked to Daesh in the country’s Sinai Peninsula.

Egypt’s Masrawy news portal, citing an army source, said on Monday the militants were killed in an operation against the Vilayat Sinai (Sinai Province) group.

According to the report, attack helicopters, planes, and ground forces were used in the operation.

Army spokesman Mohamed Samir said on Sunday some 26 “Takfiri elements” had been killed in the towns of Arish, Rafah, and Sheikh Zuweid. Samir said a number of people had also been detained at security checkpoints in the operation.

Last week, Egypt’s army said it had killed 40 Daesh-linked militants in the north of the Sinai Peninsula.

Militants from the Velayat Sinai terrorist group, previously known as Ansar Bait al-Maqdis, have claimed responsibility for a number of attacks mainly targeting the army and police. The group pledged allegiance to Daesh in November 2014.

The Egyptian army has been fighting militancy in the Sinai region for years. It launched its operation against the Velayat Sinai terrorists in September 2015.

The Sinai region is under a state of emergency since October 2014, following a deadly attack that claimed the lives of 33 soldiers.