Amnesty International said the YPG have forcibly displaced thousands of villagers in northeastern Syria.
ISIS's overall numbers remain unchanged, two Pentagon officials told USA Today.
Islamic State fighters have seized villages close to the northern city of Aleppo from rival insurgents.
The much criticized "train and equip" program to fight ISIS and Assad is on pause, probably forever.
After Pentagon's training program falls flat, Defense Secretary Ash Carter announces overhaul.
The program was troubled from the start, with some of the first class of less than 60 fighters coming under attack from al Qaeda's Syria wing.
If confirmed, the crashes would be a blow to the military strength Russia aimed to display in Syria.
Some of the U.S.-trained rebels handed over some of their equipment to Nusra last week in return for safe passage.
The U.S. military's announcement was the latest blow to a troubled effort in the fight against ISIS.
Republican senators condemned the program as a "total failure."
The terror group has captured five more villages in northern Aleppo, described as a 'major turning point' by analysts.
Assad knows the rebels' backers are not interested in a decisive rebel victory.
The insurgents are trying to drive into the Sahl al-Ghab plain, the heartland of Assad's Alawite sect.
The UK is to send military trainers to aid the fight against ISIS, the defence secretary confirms.
Mouhannad Droubi was arrested over a "torture-like" assault in Syria that was recorded.
The trainers will work with moderate Syrian opposition forces who will battle Islamic State fighters, the Pentagon said on Friday.
The British-based Syrian Observatory for Human Rights said a number of armed groups in Aleppo had agreed to the alliance, including factions from the Islamic Front, which was a merger of rebel groups announced last year.
But Obama did initially hire him for his candor…what did he expect?
The House approved the measure authorizing the training plan until Dec. 11. It was attached to a stopgap spending spill also expected to pass.
New details emerge about atrocities committed by jihadists who razed a village.