Reuters cameraman Fadel Shana, a 23-year-old Palestinian, was killed in the Gaza Strip on Wednesday while covering events in the enclave for the international news agency. He had been filming an Israeli tank dug in about 1,000 yards away.

“Human Rights Watch’s investigations at the site found evidence suggesting that an Israeli tank crew fired recklessly or deliberately at the journalist’s team,” the New York-based group Human Rights Watch said in a statement.

Local doctors said on Thursday that tiny darts sprayed from a controversial missile used by Israel killed Shana, although Israeli forces would not say whether one of their tanks fired the fatal shot.

The last few seconds of video shot on Shana’s tripod-mounted camera show the tank firing, then a midair explosion consistent with the burst of a missile.

Reuters previously reported that Shana’s soundman, Wafa Abu Mizyed, was wounded in the arm and at least two teenage bystanders were also killed in the incident.

Human Rights Watch quoted the Palestinian Center for Human Rights as saying three bystanders were killed as they watched Shana filming. It identified them as Ahmed ‘Aaref Farajallah, 14, Ghassan Khaled Abu ‘Otaiwi, 17, and Khalil Isma’il Dughmosh, 22.

“Israeli soldiers did not make sure they were aiming at a military target before firing, and there is evidence suggesting they actually targeted the journalists,” said Joe Stork, Middle East director at Human Rights Watch.

“Israel should investigate these deaths and, if crimes were committed, hold to account those responsible.”

Human Rights Watch said interviews with an eyewitness to the shelling, a resident in a nearby village and a journalist who arrived just after the attack, as well as camera footage taken by Shana, indicated there was no military activity by Palestinian militants at the scene of the attack.

An Israeli military spokeswoman has said she could not confirm a tank fired at the cameraman and could not comment on weaponry it might have used. She added that the army, which has expressed regret, hoped to cooperate with Reuters to study the incident.

Troops killed 17 Palestinians, including several civilians, on Wednesday after three Israeli soldiers were killed in clashes in the Hamas Islamist-controlled enclave