ABU DHABI, 22nd February 2016 (WAM) — War crimes are “rampant” in Syria, and the conflict has become “a multisided proxy war steered from abroad by an intricate network of alliances,” U.N. investigators said in a new report Monday.

In a swipe at the U.S., Russia and their allies, the Independent International Commission of Inquiry on Syria noted that the international powers and regional countries ostensibly pushing for a peaceful solution are the same nations that “continue to feed the military escalation.”

The new report came as U.S. officials said the U.S. and Russia had agreed on a new cease-fire for Syria that will take effect on Saturday. A “cessation of hostilities” announced earlier this month and set to begin last week did not take place, while Russian airstrikes continued to support a Syrian regime offensive in the northern province of Aleppo, according to the AP.

The U.N. investigators warned that “the fractured Syrian state is on the brink of collapse” and said there is a growing risk of “internationalisation of the conflict.”

Crimes against humanity continue to be committed by the regime forces and ISIL extremist group, their report said.

The investigators urged the U.N. Security Council to take action to bring the perpetrators to justice, possibly by referring the situation in Syria to the International Criminal Court or to “an ad hoc tribunal.”

Their report said the Syrian military is facing a severe shortage of manpower, which has forced it to rely on a growing number of foreign militia in recent attacks, “implying an increasing fragmentation of the government forces and the decentralisation of Syrian state authority.”

While ISIL remains in control of large swathes of east and northeast Syria, the investigators said it has recently come under mounting pressure from different fighting groups. One result is its reversion to tactics including the use of explosive devices and the carrying out of operations in enemy territory, often using sleeper cells.

“While no party seems able to achieve ‘victory,’ all appear to have sufficient capacity to sustain operations for the foreseeable future, perpetuating death and destruction along the way,” the investigators said.

WAM/MMYS