The militant factions include the Al Aqsa Martyrs’ Brigade, Palestinian Islamic Jihad and the Qassem Brigades, who fight under the banner of the Jenin Battalion. The authority says that its forces have “advanced in very important ways” in the camp.

JENIN, West Bank — The black-clad militants of Jenin refugee camp raced through sewage-filled alleyways to dodge gunfire echoing all around. “Quickly,” a Palestinian fighter urged as they weaved through a network of armed patrols and improvised barricades. “Watch out,” another warned at a juncture where an improvised explosive was being set.

The Palestinian Authority insists that its operation in the Jenin refugee camp was intended to maintain security and thwart any Israeli plans for the West Bank. Yet other Palestinian factions have criticized the move,