Bordered by lemon trees on one side and an olive grove on the other, the country lane leading to Joher Al Dik, where Fadel Shana was killed doing his job, was all but deserted yesterday afternoon. But two teenage boys from the Nusseirat refugee camp displayed half a dozen of the dull, black, inch-long darts which they said they had found among the cactus growing along the verge opposite where Mr Shana had parked his unarmoured SUV to film a tank on Wednesday afternoon.

According to doctors who examined the body of the 23 -year-old Palestinian Reuters cameraman at Gaza City's Shifa Hospital, it was controversial darts like those, flechettes, fired from an Israeli tank shell that explodes in the air, that caused his death. X-rays displayed to Reuters showed several of the flechettes embedded in the dead man's chest and legs, and more were found in his flak jacket, clearly emblazoned, like his vehicle, with "TV" and "Press" signs.

Mr Shana, unmarried, and a talented and popular member of the award-winning, 15-strong Reuters team in the Gaza Strip, had been driving west along the normally quiet road when he and his soundman, Wafa Abu Mizyed, 25, decided to park their vehicle 200 metres or so short of Gaza's main north-south Salahadin Road. They had been touring Gaza to report on the worst day of violence since early March.

Download the new Independent Premium app Sharing the full story, not just the headlines

A charred black patch yesterday marked the spot where the vehicle, its rear ripped to pieces by the blast, had been towed away.

Mr Shana set up his tripod and faced back east in the direction of the Israeli border to film a tank perhaps a kilometre and a half away across the fields. The last video from Mr Shana's camera showed the tank opening fire. Two seconds later, after the shot raises dust around the tank's gun, the tape goes blank – presumably marking the precise moment at which he was hit. Reuters reported yesterday that a frame-by-frame examination of the tape shows the shell exploding and dark shapes shooting out of it.

The Israeli military was silent last night on whether it planned to launch the "swift, honest, and impartial investigation" into Mr Shana's death, urged by David Shlesinger, the editor-in-chief of Reuters News, who said the medical evidence underlined the case for such an inquiry. While expressing "sorrow" for Mr Shana's death, a military official said the area was one in which there was "ongoing fighting against armed, extreme and dangerous terrorist organisations on a daily basis". The presence of media, photographers and other uninvolved individuals in areas of warfare is extremely dangerous and poses a threat to their lives." But Mr Shlesinger said: "The markings on Fadel Shana's vehicle showed clearly and unambiguously that he was a professional journalist doing his duty. We and the military must work together urgently to understand why this tragedy took place and how similar incidents can be avoided in the future. This tragic incident shows the risks journalists take every day to report the news."

The military would only say that all its weapons "are legal under international law". Israel's Supreme Court rejected a 2003 petition arguing that the use of flechettes as an anti-personnel weapon contravened a 1980 UN convention, but the Israeli human rights group Btselem said last night that flechettes violated international law and demanded a criminal investigation.

Mr Shana's friend and colleague Wissam Nassar, also 23, a photographer with the Maan news agency, said yesterday that, alerted to reports of civilian casualties in central Gaza, he and two colleagues had driven south in the armoured car of photographer Mohammed Abed, of Agence France Presse.

"We parked the car at the corner [of the lane] and saw people looking east. We saw Wafa Abu Mizyed [who was injured by shrapnel in the blast] and he was saying 'Fadel died'." Mr Nassar added that before they managed to get to Mr Shana's car there was an explosion perhaps 30 metres away from what he presumed was another tank shell, which had landed ahead of them to the east of the car.

"We all lay down in the road," he said. "I thought at first I had been injured. There was a lot of smoke." Eventually they reached Mr Shana's car and found his body beside his mangled tripod.

The two teenage boys from Nusseirat, Tareq al-Bana, 16, and Mohammed Abu Hajaj, 19, said they had been there when Mr Shana had been killed by the explosion which also injured or killed several other Palestinians, including at least one teenager with a bicycle. They said some tyres had been burned in the lane but that there had been no shooting from Palestinians.

Mr Nassar said Mr Shana was a fine colleague "who always wanted to make an extra effort. He thought a lot about the future. He really wanted to be something in Reuters." He had photographed Mr Shana last Friday when they met on duty outside a mosque where Hamas's leader, Ismail Haniyeh, was speaking.

The picture shows a smiling man in sunglasses with stubble and hair down to his neck. Mr Nassar added: "He joked with me, saying keep those pictures; you may need them some day."