By MOHAMMED JAHJOUH and SAMY MAGDY

MUWASI, Gaza Strip (AP) — Chaos erupted on the second day of aid operations by a new U.S.-backed group in Gaza as desperate Palestinians overwhelmed a center distributing food on Tuesday, breaking through fences. Nearby Israeli troops fired warning shots, sending people fleeing in panic.

An AP journalist heard Israeli tank and gunfire and saw a military helicopter firing flares. The Israeli military said its troops fired the warning shots in the area outside the center and that “control over the situation was established.”

At least three injured Palestinians were seen by the Associated Press being brought from the scene, one of them bleeding from his leg.

The distribution hub outside Gaza’s southernmost city of Rafah had been opened the day before by the Gaza Humanitarian Foundation, which has been slated by Israel to take over aid operations. The U.N. and other humanitarian organizations have rejected the new system, saying it won’t be able to meet the needs of Gaza’s 2.3 million people and allows Israel to use food as a weapon to control the population. They have also warned of the risk of friction between Israeli troops and people seeking supplies.

Palestinians have become desperate for food after nearly three months of Israeli blockade pushed Gaza to the brink of famine.

Palestinians at the scene told AP that small numbers of people made their way to the GHF center Tuesday morning and received food boxes. As word spread, hundreds of thousands of men, women and children walked for several miles from the sprawling tent camps along Gaza’s Mediterranean coast. To reach the hub, they had to pass through nearby Israeli military positions.

At the center, they waited in long, slow lines in fenced-in corridors. Two people said each person was searched and had their faces scanned for identification before being allowed to receive the boxes. Crowds swelled and turmoil erupted, with people tearing down fences and grabbing boxes. The staff at the site were forced to flee, they said.

The AP journalist positioned some distance away heard gunfire and rounds of tank fire. Smoke could be seen rising from where one round impacted. He saw a military helicopter overhead firing flares.

“There was no order, the people rushed to take, there was shooting, and we fled,” said Hosni Abu Amra, who had been waiting to receive aid. “We fled without taking anything that would help us get through this hunger.”

“It was chaos,” said Ahmed Abu Taha, who said he heard gunfire and saw Israeli military aircraft overhead. “People were panicked.”

Crowds were seen running from the site. A few managed to secure aid boxes — containing basic items like sugar, flour, pasta and tehini — but the vast majority left empty-handed.

In a statement, GHF said that because of the large number of Palestinians seeking aid, staff at the hub followed the group’s safety protocols and “fell back” to allow them to dissipate, then later resumed operations.

A spokesperson for the group told the AP that no shots were fired from GHF. Speaking on condition of anonymity in line with the group’s rules, the spokesperson said the protocols aim at “avoiding loss of life, which is exactly what happened.”

GHF uses armed private contractors to guard the hubs and the transportation of supplies. The hub is also close to Israeli military positions in the Morag Corridor, a band of territory across the breadth of Gaza that divides Rafah from the rest of the territory.

GHF has set up four hubs around Gaza to distribute food, two of which began operating on Monday — both of them in the Rafah area.

The U.N. and other humanitarian groups have refused to participate in GHF’s system, saying it violates humanitarian principles. They say it can be used by Israel to forcibly displace the population by requiring them to move near the few distribution hubs or else face starvation – a violation of international law. They have also opposed the use of facial recognition to vet recipients.

Israeli Prime Minister Benjamin Netanyahu on Tuesday commented on the turmoil at the Rafah center, saying, “There was some loss of control momentarily … happily we brought it under control.”

He repeated that Israel plans to move Gaza’s entire population to a “sterile zone” at the southern end of the territory while troops fight Hamas elsewhere. Hamas has been designated as a terrorist organization by the United States, Canada and the European Union.

Israel has said the new system is necessary because it claims Hamas has been siphoning off supplies that reach Gaza. The U.N. has denied that any significant diversion takes place.

Throughout the war, the U.N. and other aid groups have conducted a massive operation distributing food, medicine and other supplies to wherever Palestinians are located. Israel says GHF will replace that network, but the past week has allowed a trickle of aid to enter Gaza for the U.N. to distribute.

COGAT, the Israeli military agency in charge of coordinating aid, said on Tuesday that 400 trucks of supplies, mainly food, was waiting on the Gaza side of the main crossing from Israel, but that the U.N. had not collected them. It said Israel has extended the times for collection and expanded the routes that the U.N. can use inside Gaza.

Jens Laerke, spokesperson for the U.N. humanitarian office OCHA, told reporters in Geneva that agencies struggle to pick up the supplies “because of the insecure routes that are being assigned to us by the Israeli authorities to use.” He said the amount of aid allowed the past week was “vastly insufficient.”

Magdy reported from Cairo. Associated Press correspondents Wafaa Shurafa in Deir al-Balah, Gaza Strip, Sam Mednick in Tel Aviv and Lee Keath in Cairo contributed to this report.