The Palestinian Red Crescent Society said an Israeli strike on an ambulance in the central Gaza Strip on Wednesday killed four medics and two other people inside the vehicle.
The organisation said in a statement there were "six martyrs" as a result of "the IDF (Israeli army) targeting of a PRCS ambulance in Deir al-Balah," adding that four were emergency team members.
The Red Crescent had initially said four people had died but revised the figure, saying "two individuals who were in the ambulance at the time of the targeting sustained injuries and were later martyred".
The Israeli military did not immediately comment on the incident when contacted by AFP.
Jagan Chapagain, the head of the International Federation for Red Cross and Red Crescent Societies, called the attack "unacceptable" in a social media post and said "I strongly condemn their killing."
He added: "Protection of patients and health care workers is not negotiable. They must never be targeted."
The Red Crescent said the ambulance had been on Salah al-Din Road, a highway running north-south through the Gaza Strip that has in the past been used by thousands of Palestinians fleeing the Israeli military advance.
Earlier on Wednesday afternoon, the health ministry in Hamas-run Gaza said multiple people were killed in an Israeli strike near a hospital in Deir al-Balah.
Over 23,350 people have been killed, mostly civilians, in more than three months of war between Hamas and Israel, according to the latest Gaza health ministry toll.
Before Wednesday's ambulance strike, the health ministry said more than 120 ambulances had been destroyed and at least 326 healthcare workers killed since the start of the conflict.
The war erupted with the bloody Hamas attack on Israel on October 7, which resulted in around 1,140 deaths in Israel, mostly civilians, according to an AFP tally based on official figures.
The Israeli military says 186 soldiers have since been killed fighting in Gaza.
