The U.N. Security Council says it plans to impose sanctions on the leaders of a Congolese rebel group and others who have violated an arms embargo on the country.

The council also expressed its “deep concern” over reports that the Congolese militia group known as M23 is receiving help from neighboring countries.

U.N. experts have accused both Uganda and Rwanda of supporting the rebellion in Congo's east, a charge both countries deny.

In its statement Friday, the U.N. Security Council stressed the urgency for dialogue between the government of the Democratic Republic of Congo and its neighbors, especially Rwanda.

The DRC government has struggled to bring order to the east of the country for years. New unrest flared up in April when the army began battling M23.

The militia originated as another rebel group that was integrated into the army in 2009. It takes its name from a peace accord that the rebels say was violated by the government.

Human Rights Watch accuses the rebel group of committing widespread war crimes, including rapes, killings, abductions and recruiting children to work as soldiers.

Fighting between the government and M23 has displaced hundreds of thousands of people.