GAZA CITY: Authorities in Hamas-ruled Gaza declared treason charges Wednesday against the leader of a rival armed group accused of working with Israel during its Gaza offensive, ordering him to turn himself in.

Yasser Abu Shabab, aged 35 according to Hamas's summons issued on Wednesday, is suspected of heading the Popular Forces group in southern Gaza.

Palestinian media say the group operates in the east of the southern city of Rafah in an area controlled by Israeli forces as they battle Hamas in the territory.

The "military judiciary authority" of the government in the Hamas-ruled territory ordered him "to surrender himself to the competent authorities for trial before the judicial bodies".

It said in a statement that its "revolutionary court" had "given Yasser Abu Shabab 10 days to turn himself in for trial on charges of treason, collaborating with hostile entities, forming an armed gang, and armed rebellion".

Israeli Prime Minister Benjamin Netanyahu admitted last month that Israel was supporting an armed group in Gaza that opposes Hamas, without naming it.

Israeli and Palestinian media named the group as the Popular Forces, led by Abu Shabab.

The European Council on Foreign Relations think tank described Abu Shabab as the leader of a "criminal gang operating in the Rafah area that is widely accused of looting aid trucks".

It said he was thought to have been previously imprisoned by Hamas for drug-trafficking.

The Popular Forces said in a statement on Sunday that they had raided a site where they said Hamas was storing food aid meant for civilians.

Hamas has accused the Popular Forces of collaborating with Israel to loot humanitarian aid.