Egyptian security forces on Monday found four more dead bodies in the northern Sinai Peninsula, shortly after three bodies were discovered in the area, a security source has said.

"The four bodies were found by locals after being dumped by unidentified militants on main roads [in the province]," the source, requesting anonymity, told The Anadolu Agency.

He noted that marks of gunshots appeared on the bodies of the victims.

Earlier Monday, three bodies had been found in North Sinai.

The source said that that investigation suggested that the Wilayat Sinai (State of Sinai) militant group was behind the killings.

On Saturday, three bodies – two of which were decapitated – were found in northern Sinai.

According to local residents and security sources, several people in the area have been kidnapped by militants within the past two weeks.

It is believed that militant groups in Sinai kill those suspected of "collaborating" with the Egyptian or Israeli authorities.

Wilayat Sinai used to be known by the name "Ansar Beit Al-Maqdis", but it changed its name in November of 2014 after it swore allegiance to the ISIL, a militant group that has captured vast territories in both Iraq and Syria.

The group claimed responsibility for most attacks against the Egyptian army and policemen across Egypt in the past months.

On Sunday, the militant group claimed responsibility for kidnapping an Egyptian police officer in Sinai as well.