As many as 600 people were held in a hospital overnight, the mayor of the city of Jenin told a Palestinian news agency. The death toll from the two-day operation rose to 10, officials said.

Prime Minister Benjamin Netanyahu said the assault on Jenin would be “extensive and significant,” as the military erected new checkpoints across the West Bank.

Israel captured the West Bank, Gaza and east Jerusalem in the 1967 Mideast war, and Palestinians want all three territories for their future state. Escalations in one area frequently spill over, raising further concerns that the second and far more difficult phase of the Gaza ceasefire — which has yet to be negotiated — may never come.