Israeli tanks moved into the occupied West Bank on Sunday for the first time in decades in what Palestinian authorities called a “dangerous escalation,” after the defense minister said troops will remain in parts of the territory for a year and tens of thousands of Palestinians who have fled cannot return.

Israel’s defense minister, Israel Katz, said that 40,000 Palestinian residents displaced from militant hotbeds would not be allowed to return to their homes.

The Israeli military is expanding its operations in the occupied West Bank and will remain in some refugee camps for the “coming year,” Defense Minister Israel Katz said Sunday.