Israel used at least one US-made precision-guided bomb during a strike on a school and mosque in Gaza City that killed more than 90 people, according to a weapons expert.

Footage from the aftermath of the attack, filmed by CNN, showed parts of an explosive device that former US Army explosive ordnance disposal technician Trevor Poole confirmed was from a GBU-39 small diameter bomb.

According to weapons expert Chris Cobb Smith, the GBU-39, made by Boeing, is a high-precision munition "designed to attack strategically important targets" while causing low collateral damage.

When asked about the strike, an Israeli military official told CNN that Israeli forces used "three small, precise munitions that could not have caused the damage the Palestinians claim they did."

But Cobb Smith, a former British Army artillery officer, said: "The use of any munition, even of this size, would always entail risks in a densely populated area."

Paul added that it was possible that this munition was responsible for the high death toll reported by officials in Gaza, but added that it depended on how many people were inside the targeted rooms or in adjacent sections.

According to officials in Gaza, the complex was bombed during dawn prayers, which would explain the presence of a larger number of civilians at the site.