"The impression we got is that there were originally two babies."
The Israeli military said it had no comment.
Danish Siddiqui had been embedded with the Afghan special forces at the time.
Foreign forces, including the US, are withdrawing after almost 20 years of fighting.
The fire was caused by an explosion from a "normal accident" in a container holding flammable material, officials said.
It comes in response to drone attacks by the militia against US personnel.
Human rights groups say he played a role in the extrajudicial killings of thousands of political prisoners in 1988.
Hamas radio initially reported the Israeli airstrike on Gaza.
Documents show officials were well aware of their potential deployment to Yemen.