The Al-Aqsa Martyrs Hospital in the central city of Deir al-Balah was already struggling to treat a large number of wounded people from an earlier strike on a school-turned-shelter nearby that killed at least 20 people when the early morning airstrike hit and fire engulfed many of the tents.
The Hezbollah attack on central Israel was the deadliest since Israel began its ground invasion of Lebanon two weeks ago.
An Israeli strike on the central Gaza Strip killed a family of eight, and Israeli forces waged air and ground campaigns in the territory's north, with Palestinians fearing Israel intends to permanently depopulate the area.
A tent encampment caught fire early Monday on the grounds of a hospital complex in central Gaza after the Israeli military carried out a strike on the compound, where it said Hamas fighters had been embedded.