"Those who cooperate and provide information to the army and help in the "sinful" attacks on villages are partners in the war against Islam," Sinai-based group Al-Salafiya Al-Jihadiya said in a statement late Friday.
The group described those helping the military as "apostates who deserve death" and urged them to "repent".
Depicting the Egyptian army as a group of "apostates" and "benefactors" of Jews and Crusaders, the statement branded the ongoing military operations in Sinai "are a war against Islam and sharia".
Egyptian officials could not be reached for comment.
Egypt's Sinai Peninsula, which shares borders with both Israel and the Gaza Strip, has seen almost daily attacks by unknown gunmen since the July 3 ouster of elected President Mohamed Morsi by the country's powerful military establishment.
The Egyptian army is currently carrying out what military experts are calling the largest military operation in the borderland of Sinai with the stated aim of combating "militancy and terrorism".