At least two Egyptian policemen have been killed when unidentified armed men opened fire on them in the North African country’s embattled Sinai Peninsula.

The Egyptian Interior Ministry said in a statement on Sunday that “a police captain and a policeman died of their wounds after unknown assailants shot them” late on Saturday in the city of el-Arish, situated 344 kilometers (214 miles) northeast of the capital, Cairo.

No individual or group has claimed responsibility for the assault, yet. Security forces have launched an investigation into the attack, and a search for the assailants is under way.

On September 29, an Egyptian police officer was killed and another injured in an attack by armed men against their patrol vehicle in the el-Baragil district of Egypt’s central province of Giza.

The development came more than a week after two policemen were injured in a bomb blast near an Egyptian Foreign Ministry building in the Agouza district of Giza.

On September 26, at least two policemen were killed and over a dozen others injured in a roadside bomb explosion just outside the city of el-Arish, located about 344 kilometers (214 miles) northeast of the capital, Cairo.

The Egyptian military has been engaged in operations to quell acts of terrorism and militancy in the Sinai Peninsula. It views the volatile region as a sanctuary for extremists, who use it as a safe haven.

The militant group Velayat Sinai, previously known as Ansar Bait al-Maqdis, has claimed responsibility for most of the attacks in Sinai. Last November, the group pledged allegiance to the Takfiri Daesh terrorist group, which is mainly operating in Iraq and neighboring Syria.