U.N. human rights investigators accused the Syrian government on Monday of using local militias, known as Popular Committees, to carry out mass killings. 

"In a disturbing and dangerous trend, mass killings allegedly perpetrated by Popular Committees have at times taken on sectarian overtones," the U.N. commission of inquiry on Syria said in its most recebt report to the U.N. Human Rights Council in Geneva.

"Some appear to have been trained and armed by the government," they said.

The local militias, "are alleged to be participating in house-to-house searches, identity checks, mass arrests, looting and acting as informants," the investigators claimed in a 10-page report.