Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. UN Chief Condemns Deadly Attack on Peacekeepers in DRC by Margaret Besheer UNITED NATIONS -- The United Nations secretary-general has expressed his "outrage" after an attack on U.N. peacekeepers in the eastern Democratic Republic of Congo that killed at least a dozen Tanzanian peacekeepers and injured 40 more. "I condemn this attack unequivocally," António Guterres said. "These deliberate attacks against U.N. peacekeepers are unacceptable and constitute a war crime." The U.N. chief said the attack occurred late Thursday in troubled North Kivu province. "This is the worst attack on peacekeepers in the organization's recent history," Guterres said. A U.N. official told VOA that the attack on the mission's forward operating base in Semuliki in Beni territory was likely perpetrated by the Ugandan rebel group the Allied Democratic Forces (ADF), which is active in the area and has attacked the mission in the past month. The peacekeepers were part of a special intervention force based in eastern Congo. The U.N. mission, MONUSCO, said at least five Congolese soldiers were also killed in the protracted fighting between suspected ADF elements and MONUSCO and Congolese forces. "Military reinforcements have arrived on the scene, the force commander is there as well, coordinating the mission's response and the medical evacuation of casualties is ongoing," Guterres added. "Attacks against those who are working in the service of peace and stability in the Democratic Republic of the Congo are cowardly and constitute serious violations," said MONUSCO chief Maman Sidikou in a statement. "MONUSCO will take all actions to ensure that the perpetrators are held accountable and brought to justice."