At least four Palestinians have been killed by Israeli fire as they were heading to an aid distribution centre, health workers in Gaza have said.

The Israel Defense Forces (IDF) said troops had directed warning shots after issuing a verbal challenge at a group that was moving towards them and was deemed a threat.

It is the latest deadly incident to occur near aid distribution points in Gaza that have been set up by a new organisation, the Gaza Humanitarian Foundation (GHF), which is backed by Israel and the US.

The IDF said it was aware of reports that people had been injured, adding: “The number… does not align with the information currently held by the IDF.”

The latest incident occurred before dawn near an aid distribution site close to Rafah in the south of Gaza.

Palestinian paramedics said they had evacuated four people who were killed, as crowds gathered in the hope the aid centre would open and they could get food.

One woman said her husband was shot in the head as he was waiting to collect food for their family.

The Israeli army has declared that Palestinians should only move to and from the GHF distribution sites between 06:00 and 18:00 local time – and that at all other times it should be considered an “active combat zone”.

The GHF has said it opened three sites on Sunday – one in central Gaza at 06:00 and then two more in Rafah at noon.

Israel recently began to allow limited aid into Gaza after a three-month blockade, prioritising distribution through the GHF.

But the foundation has been mired in controversy, after several deadly incidents took place during its first week of operation.

More than 60 Palestinians were killed by gunfire over the foundation’s first three days distributing aid, according to reports from medics and local health authorities.

Multiple witnesses blamed Israeli soldiers for the killings.

The IDF said it had fired warning shots on the first two days and shot near to Palestinian suspects advancing towards their positions on the third, adding that it is investigating the incidents.

On Saturday, six Palestinians were killed and several others were wounded by Israeli gunfire, the Hamas-run Civil Defence agency said.

The Israeli military again said it fired warning shots at suspects who approached them in a threatening manner.