KIGALI, Rwanda The government of the Democratic Republic of Congo on Thursday strongly condemned the massacre last month of more than 300 civilians in the country’s east by M23 rebels, despite a ceasefire agreement signed in Doha. The UN Human Rights Office, citing firsthand accounts, said Wednesday that at least 319 civilians were killed by the M23 in a series of attacks on four villages in North Kivu province in July. “This toll, one of the heaviest recorded since the resurgence of the M23,