DAKAR, Senegal — A human rights group says at least 321 civilians were killed by the Lord's Resistance Army in Congo in a previously unreported massacre in late 2009.

New York-based Human Rights Watch adds that at least 250 people were abducted by the rebels, including at least 80 children during the killing spree in the Makombo area of northeastern Congo.

Senior Africa researcher Anneke Van Woudenberg calls the massacre "one of the worst ever committed by the LRA in its bloody 23-year history."

Yet the massacre targeting at least 10 villages, which occurred from Dec. 14-17, 2009, went unreported for months.

The LRA is a Ugandan rebel movement that was pushed out of Uganda and is now in a tropical forest straddling the border between Congo and the Central African Republic. (AP)