Illicit trafficking of diamonds from Central African Republic into neighbouring Cameroon is helping finance the continuation of a nearly three-year conflict, an expert panel that monitors U.N. sanctions said in a confidential report.

Central African Republic (CAR) descended into chaos in March 2013 when predominantly Muslim Seleka rebels seized power, triggering reprisals by “anti-balaka” Christian militias who drove tens of thousands of Muslims from the south in a de facto partition of the landlocked country.

Although rival armed groups agreed to a peace accord in May, the conflict has continued at a lower intensity, and a transitional government has been unable to assert its authority over all of the vast, mineral-rich territory.

The export of diamonds from CAR was banned in May 2013 by the Kimberley Process, which represents 81 countries, including the United States, the European Union, Russia, China and all major diamond-producing nations. The group was formed to prevent so-called blood diamonds from funding conflicts.

In its interim report to the CAR sanctions committee, the U.N. Security Council’s panel of experts said the illicit trade in diamonds is still funding major players in the conflict and increasingly involves neighbouring countries such as Cameroon and Chad.

The panel has not previously highlighted the role of Cameroon in the conflict diamond trade. But the report does not directly implicate Cameroon authorities in the trade.

“Despite a decline in violence by anti-balaka elements in the southwest, some anti-balaka continue to be involved in the illicit exploitation of diamonds,” the panel said in the report, seen by Reuters.

“Diamond mines in the (sub-prefecture) of Amada Gaza (Mambere-Kadei province) are violently contested between anti-balaka and armed Peul,” the experts said.

Many Muslims from the Peul ethnic group were displaced by the war.

The panel has said that all sides in the conflict profit from the trade in diamonds. It estimates that some 140,000 carats of diamonds, valued at $24 million, have been smuggled out of the country since the 2013 ban on the export of CAR’s rough diamonds.

Its latest report said that diamonds from Amada Gaza were suspected to have been trafficked through Gbiti, a Cameroon border town. Other examples of cases the panel is investigating include diamond trafficking through the Cameroonian town of Kenzou, including a large, 40-carat stone.

Another involves the seizure of 160 carats of undocumented diamonds worth around $28,000 in Yaounde, Cameroon in April. These diamonds, the panel said, had been carried from Kenzou by two Indian nationals who recently visited Bangui, CAR’s capital.

Cameroon’s U.N. Mission did not respond to a request for comment.

Armed anti-balaka elements, the panel said, are involved in illicit diamond exploitation at a number of mining sites.

The panel of experts recommended that the Security Council urge transitional CAR authorities to suspend diamond-trading houses that purchase the gems from areas “under direct or indirect control of armed groups.” It also said the council should urge neighbouring countries not to violate CAR’s borders.

MINUSCA, the U.N. peacekeeping force in CAR, was deployed in 2014 to shore up the precarious stability established under the transitional government. A U.N. sanctions regime for Central African Republic, which includes an arms embargo, was set up in December 2013.

In May 2014, the Security Council blacklisted former President Francois Bozize and two other men, one of whom has since died. Last month it blacklisted the Belgian branch of CAR’s diamond-trading company and three individuals linked to the conflict.

CAR presidential and legislative elections are scheduled for Oct. 18. They have already been postponed several times, however, and the transitional government said on Tuesday the vote was unlikely to take place on time.