Three bodies were found shot in the head in the south of Arish in Sinai Sunday, reported Reuters' Aswat Masriya.
The three young men belong to renowned tribes in Northern Sinai, security officials told Aswat Masriya.
Several corpses were also found decapitated by Sinai locals in September.
A video published on online jihadist forums in early October said that jihadist group Ansar Bayt Al-Maqdis had decapitated three people and shot a fourth for "collaborating" with Israel's Mossad spy agency and the Egyptian army.
The group published a previous decapitation video of four others in August who they said had provided information that helped an Israeli drone strike kill three of the group's fighters in July.
Security forces and Islamist militants have been fighting in Sinai, as an Islamist insurrection following the ouster of former president Mohamed Morsi continues.
It is not clear whether Sunday's shooting is related to the ongoing war in Sinai.
A fact-sheet prepared by Egypt's foreign affairs ministry stated that the number of terrorism-related deaths between January 2011 and April 2014 was 971, including 664 security personnel.
Short link: