JERUSALEM >> Israel is supporting armed groups of Palestinians in Gaza in what it says is a move to counter Hamas. But officials from the U.N. and aid organizations say the military is allowing them to loot food and other supplies from their trucks.

One self-styled militia, which calls itself the Popular Forces, led by Yasser Abu Shabab, says it is guarding newly created, Israeli-backed food distribution centers in southern Gaza. Aid workers say it has a long history of looting U.N. trucks.

Gaza’s armed groups have ties to powerful clans or extended families and often operate as criminal gangs. Aid workers allege Israel’s backing of the groups is part of a wider effort to control all aid operations in the strip.

Israel denies allowing looters to operate in areas it controls. Prime Minister Benjamin Netanyahu said in a social media video Thursday that Israel had “activated” clans in Gaza to oppose Hamas.

He didn’t elaborate how Israel is supporting them or what role Israel wants them to play. Netanyahu’s comments were in response to a political opponent accusing him of arming “crime families” in Gaza.

Clans, tribes and extended families have strong influence in Gaza, where their leaders often help mediate disputes. Some have long been armed to protect their group’s interests, and some have morphed into gangs involved in smuggling drugs or running protection rackets.

After seizing power in 2007, Hamas clamped down on Gaza’s gangs — sometimes with brute force and sometimes by steering perks their way.

But with Hamas’ weakening power after 20 months of war with Israel, gangs have regained freedom to act. The leadership of a number of clans — including the clan from which the Abu Shabab group’s members hail — have issued statements denouncing looting and cooperation with Israel.

The Abu Shabab group went public in early May, declaring itself a “nationalist force.” It said it was protecting aid, including around the food distribution hubs run by the Gaza Humanitarian Foundation, a mainly American private contractor that Israel intends to replace the U.N.-led aid network.