Doctors at Gaza's largest hospital say crippling fuel shortages have led them to put several premature babies in single incubators as they struggle to keep the newborns alive while Israel presses on with its military campaign.

Overwhelmed medics say the dwindling fuel supplies threaten to plunge them into darkness and paralyze hospitals and clinics in the Palestinian territory, where health services have been pummeled during 21 months of war.

An Israeli military official said around 160,000 liters of fuel destined for hospitals and other humanitarian facilities had entered Gaza since Wednesday but that its distribution around the enclave was not under Israel's purview.