Israeli security forces launched an operation in the volatile West Bank city of Jenin, killing at least four Palestinians, officials said on Tuesday.
Four Palestinians have been killed and around 35 injured in Israel's military offensive on Jenin, said the health ministry.
The military said soldiers, police and intelligence services had begun a counter-terrorism action in the city, giving no further details.
Prior to the Israeli action, Palestinian security forces had been conducting a weeks-long operation to reassert control in the city and the adjacent refugee camp, a major center of armed groups in the occupied West Bank.
Palestinian health services said at least four Palestinians were killed and 35 wounded as the Israeli raid began in Jenin, where an Israeli air strike last week in the refugee camp killed at least three Palestinians and wounded scores more.
The move into Jenin, where the Israeli army has carried out multiple raids and large-scale incursions over recent years, comes only days after the start of a ceasefire in Gaza and underscores the threat of more violence in the West Bank.
Late on Monday, bands of Israeli settlers attacked Palestinians, smashing cars and burning property, just as newly installed US President Donald Trump announced he was lifting sanctions on violent settlers.
The attack near the village of al-Funduq, in an area where three Israelis were killed in a shooting earlier this month, was the latest in a long sequence of incidents that have accelerated strongly since the start of the war in Gaza.
The military said it had opened an investigation into the incident, which it said involved dozens of Israeli civilians, some in masks.