At least 27 Palestinians have been killed by Israeli fire as they attempted to collect aid near a distribution site in Gaza, local officials say.

Civilians were fired upon by tanks, quadcopter drones, and helicopters near the al-Alam roundabout, about 1km (0.6 miles) from the aid site, a spokesman for Gaza’s Hamas-run Civil Defence agency, Mahmoud Basal, said.

The Israel Defense Forces (IDF) said its troops fired shots after identifying suspects who moved towards them “deviating from the designated access routes”.

Israel previously denied shooting Palestinians in a similar incident on Sunday which the Hamas-run health ministry said killed 31 people and injured nearly 200.

Its denial was in direct contradiction to what dozens of civilian witnesses, NGOs, and health officials said.

Following Tuesday morning’s incident, the director of Nasser Hospital in Khan Younis, Atef Al-Hout, described 24 dead and 37 wounded arriving with gunshot injuries, saying Israeli forces had opened fire on “crowds of civilians waiting for aid in western Rafah.”

A foreign medic working in the area told the BBC it had been “total carnage” since 03:48 (01:48 BST) and that they had been overwhelmed with casualties.

In a video shared by a local journalist, witness Nadeem Zarab said he and his uncle began walking to the aid centre at 02:00 (00:00 BST). When they reached the roundabout “the shooting started, from the helicopter, the tanks, and the sniper soldiers”, he added.

“Gunfire was coming from all directions. We started using the wall as cover, shielding ourselves close to it.”

“People, as they were running, began collapsing in front of us. My uncle couldn’t bear it, he saw someone get shot right in front of him, so he tried to run and catch him. But I told him, ‘Come back, come back! Where are you going?'”

Another eyewitness, who did not want to be named, told BBC Arabic: “I am displaced from Khan Younis and responsible for a family of five.

“The Israeli Army informed us that we would be receiving aid through the US committee.

“When we arrived, the checkpoint opened at six o’clock. Suddenly, gunfire erupted from all directions.

They added: “Hundreds were wounded or killed, the scene was horrific. After we moved just two hundred metres, machine guns began firing at us.”

A third eyewitness, who also did not want to be named, said they had seen “intense shelling from aircraft and tanks” after arriving at the aid centre at around 05:00 (03:00 BST).

It is unclear from witness statements whether people were killed in one incident or several incidents throughout the night.

In a statement, the IDF said its troops were “not preventing the arrival of Gazan civilians to the humanitarian aid distribution sites.”

“The warning shots were fired approximately half a kilometre away from the humanitarian aid distribution site toward several suspects who advanced toward the troops in such a way that posed a threat to them,” it added.

Israel does not allow international news organisations, including the BBC, into Gaza, making verifying what is happening in the territory difficult.

Aid distribution has recently been taken over by the Gaza Humanitarian Foundation (GHF), an Israel- and US-backed group which aims to replace UN agencies and other organisations.

The GHF system requires civilians to go to distribution centres situated in areas of Israeli military control, and staffed by armed American security contractors.

Palestinians are forced to walk long distances to collect the aid – and then carry boxes of it weighing up to 20kg (44lbs) back to their homes or shelters.

The previous UN system delivered aid directly into communities – at 400 sites across Gaza. It also distributed the aid based on a registry of the population, guaranteeing everyone food.

The new system appears to operate on a first come, first serve basis, meaning Palestinians are gathering through the night to secure a place at the front of the line – before a race to collect supplies when the aid site opens hours later.

The GHF has been heavily criticised by UN bodies and the wider international community for “weaponising” aid and creating a system that goes against humanitarian principles.

Responding to Tuesday’s incident, the group said: “While the aid distribution was conducted safely and without incident at our site today, we understand that IDF is investigating whether a number of civilians were injured after moving beyond the designated safe corridor and into a closed military zone. This was an area well beyond our secure distribution site and operations area.”

UN human rights chief Volker Türk said: “For a third day running, people were killed around an aid distribution site”.

“Palestinians have been presented the grimmest of choices: die from starvation or risk being killed while trying to access the meagre food that is being made available through Israel’s militarized humanitarian assistance mechanism.”

During Sunday’s incident, the International Committee of the Red Cross (ICRC) said its hospital in Rafah received “a mass casualty influx” with 21 “declared dead upon arrival”.

The IDF said its findings from an initial inquiry showed that its forces had not fired at people while they were near or within the aid centre.

The GHF also denied the claims of injuries and casualties at its site and said they had been spread by Hamas.

Responding to Sunday’s incident, UN Secretary General António Guterres said in a statement: “I am appalled by the reports of Palestinians killed and injured while seeking aid in Gaza yesterday

“I call for an immediate and independent investigation into these events and for perpetrators to be held accountable.”

Israel launched a military campaign in Gaza in response to Hamas’ cross-border attack on 7 October 2023, in which about 1,200 people were killed and 251 others were taken hostage.

At least 54,470 people have been killed in Gaza since then, including 4,201 since Israel resumed its offensive on 18 March, according to the territory’s health ministry.