Officials say a Ugandan rebel group in eastern Congo has attacked a town close to the border, forcing thousands to flee to Uganda.

Lt. Col. Paddy Ankunda, the Ugandan army spokesman, said Friday that rebels of the Allied Democratic Forces attacked the eastern Congolese town of Kamango on Thursday, killing some people and forcing thousands to flee.

Karen Ringuette, a spokeswoman for the U.N. refugee agency in Uganda, said at least 18,000 people had since sought refuge in Uganda.

The Allied Democratic Forces, a rebel group that is opposed to the Ugandan government, staged terrorist attacks in Uganda in the 1990s before a Ugandan military onslaught forced the rebels into Congo.

A U.N. report last year said those rebels "expanded their military capacity and cooperated" with Somalia's al-Shabab militants.