Israeli operations in the West Bank have killed at least 12 Palestinians since Tuesday and could threaten the newly agreed ceasefire in Gaza, United Nations Human Rights office spokesperson Thameen Al-Kheetan said on Friday.

In the days since a fragile ceasefire took hold in the Gaza Strip, Israel has launched a major military operation in the occupied West Bank and suspected Jewish settlers have rampaged through two Palestinian towns.

Israel’s defense minister has announced a series of raids that he says are targeting “terrorism” in the occupied West Bank, as Palestinian officials warned of a “man-made disaster.”