Three fishermen were killed on Sunday when their boat exploded off the Gaza Strip, a blast that a human rights group said was likely caused by errant Palestinian rocket fire, refuting earlier reports of Israeli fire.
The Palestinian Center for Human Rights said the boat was two miles offshore when the shell hit and "completely destroyed it."
"The center condemns the incident, which indications suggest mostly likely occurred as a result of resistance training," said the statement, referring to Palestinian militant groups.
Nizar Ayash, chairman of the Gaza Fishermen's Association, said that the three fishermen were hit by a projectile near Khan Younis. He told reporters that he was unable to confirm what had caused the explosion.
He identified the fishermen as Yahya Mustafa al-Laham, and brothers Hamdi and Zakaria Higazi al-Laham.
The Israeli military said in response to reports earlier on Sunday by Palestinian media that "the Israeli navy did not fire" at the Strip, and said "our indications show that their deaths were caused by an explosion inside Gaza."
The Interior Ministry in Gaza, which is run by the Islamist group Hamas, said it was investigating the incident.
Hamas' armed wing said it opened an investigation into the "painful incident" and would publish the results as soon as possible.
Last month, the Israeli navy sank a fishing boat off the coast of the Gaza Strip, with the military saying soldiers suspected it posed a potential threat.
Reports in Gaza said it was a fishing boat that had been fired at, while the military said a preliminary investigation showed there were no weapons or explosives on board that could have endangered the soldiers. No casualties were reported thus far.
The military did not mention in its statement on the incident, which occurred off the coast of Khan Yunis in the Gaza Strip, whether anyone was wounded or killed. The statement said that a navy force had “identified naval activity that constituted a potential threat to navy vessels.”
According to security sources, a boat from Gaza approached a navy ship sailing in the area, and the soldiers, suspecting it posed a threat, communicated that it should stop – and when this failed, they fired.
DPA contributed to this report.