By Raneen Sawafta and James Mackenzie JENIN, West Bank/JERUSALEM (Reuters) -Israel sent tanks into the occupied West Bank for the first time in more than 20 years on Sunday as it ordered the military to prepare for an "extended stay" to fight Palestinian militant groups in the area's refugee camps.

Israel launched a major military incursion in the northern West Bank in August, which it called “Operation Summer Camps.” It sent armored vehicles into the cities of Jenin and Tulkarem, severing water and electricity and leading Palestinians to ration food, residents told CNN.

Associated Press journalists saw a handful of tanks move Sunday into Jenin, long a bastion of armed struggle against Israel.