A new UN report says the number of refugees fleeing the violence in the Democratic Republic of Congo has risen by more than 350,000 over the past few months.

The report to the Security Council released Monday said that as of the end of August, about 440,000 Congolese escaped into neighboring Burundi, Rwanda, and Uganda, The Associated Press reported.

In July, the Red Cross said almost 70,000 Congolese had become refugees in Uganda.

The Congolese army is battling the March 23 movement (M23) rebels with the help of the new UN intervention brigade in the east of the country. The brigade, made up of some 3,000 troops, has a stronger mandate compared to previous UN peacekeeping missions.

The intervention brigade was created after the M23 rebels invaded and briefly occupied Goma, home to about one million people, last November. The rebels withdrew from the city on December 1, 2012 under a ceasefire accord.

The M23 rebels and several other armed groups are active in the eastern Congo and are fighting for control of the country’s vast mineral resources, such as gold, the main tin ore cassiterite, and coltan (columbite-tantalite), which is used to make many electronic devices, including cell phones.

The M23 rebels defected from the Congolese army in April 2012 in protest over alleged mistreatment in the Armed Forces of the Democratic Republic of Congo (FARDC). They had previously been integrated into the Congolese army under a peace deal signed in 2009.

Since early May 2012, nearly three million people have fled their homes in the eastern Congo. About 2.5 million have resettled in Congo, but about 500,000 have crossed into neighboring Rwanda and Uganda.

Congo has faced numerous problems over the past few decades, such as grinding poverty, crumbling infrastructure, and a war in the east of the country that has dragged on since 1998 and left over 5.5 million people dead.