The Palestine Red Crescent Society said on Saturday that the fate of nine crew members in the Gaza Strip remains unknown nearly a week after Israeli forces had hit ambulances.The Israeli military said troops had opened fired on ambulances after identifying them as "suspicious vehicles", in an incident on Sunday in southern Gaza that Hamas authorities condemned as a "war crime", reporting at least one person killed.The gunfire in Rafah city's Tal al-Sultan neighbourhood came just days into a renewed Israeli offensive in the southern area, close to the Egyptian border, after the military resumed its bombardments of Gaza on March 18 following an almost two-month-long truce.The Red Crescent in a statement accused Israeli authorities of refusing to allow search operations to locate the missing workers."For the seventh consecutive day, the fate of nine Palestine Red Crescent EMTs remains unknown after they were besieged and targeted by Israeli forces in Rafah," it said."We condemn Israel's deliberate obstruction of search efforts and hold it fully responsible for the lives of our team members," the statement added.The emergency response service said that "initial reports from the crew at the time of the incident confirmed they came under heavy gunfire from Israeli forces, resulting in multiple injuries."The day after the incident, Gaza's civil defence agency said in a statement that it had not heard from a team of six rescuers from Tal al-Sultan who had been urgently dispatched to respond to deaths and injuries.On Friday, the agency reported finding the body of the team leader as well as the rescue vehicles -- an ambulance and a fire engine -- and said a vehicle from the Palestine Red Crescent Society was also "reduced to a pile of scrap metal"."The targeted killing of rescue workers -- who are protected under international humanitarian law -- constitutes a flagrant violation of the Geneva Conventions and a war crime," said Hamas political bureau member Bassem Naim.Tom Fletcher, head of the United Nations Office for the Coordination of Humanitarian Affairs, said that since March 18, Israeli air strikes have hit "densely populated areas", with "patients killed in their hospital beds. Ambulances shot at. First responders killed."The health ministry in Hamas-run Gaza said on Saturday that at least 921 people have been killed in the Palestinian territory since Israel resumed its large-scale strikes.