Israel bombarded Gaza early Friday, hitting areas in the south where Palestinians had been told to seek safety, and it began evacuating a sizable Israeli town in the north near the Lebanese border, the latest sign of a potential ground invasion of Gaza that could trigger regional turmoil.

Palestinians in Gaza reported heavy airstrikes in Khan Younis in the south, and ambulances carrying men, women and children streamed into the town’s Nasser Hospital, Gaza’s second largest, which is already overflowing with patients and people seeking shelter. The Israeli military said it had struck more than 100 targets across Gaza linked to the territory’s Hamas rulers, including a tunnel and arms depots.