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 has stepped up its raids in West Bank towns and cities over the weekend in an apparent response to bus bombings near Tel Aviv last week.

The country also called for the UN Relief and Works Agency to be allowed to continue its work in the region and noted that the UN International Court of Justice has ruled that the Israeli presence in the Palestinian territories is illegal.