At least 66 people have been killed in eastern Democratic Republic of Congo by rebels linked to the Islamic State group, local officials said on Saturday.Fighters from the Allied Democratic Forces (ADF), an Islamist group with ties to IS, attacked civilians in the Irumu area of Ituri province, which borders Uganda. The attack comes as eastern Congo may see an end to its ongoing war with the M23 rebel group, which is backed by neighbouring country Rwanda.Jean Tobie Okala, spokesperson for the United Nations mission in Ituri, described the attack as a “bloodbath.”“Around 30 civilians were killed between Thursday and Friday, July 11, in the Walese Vonkutu chiefdom, Irumu territory, in Ituri,” Okala said, as reported by news agency AP. “Based on information from civil society, the death toll has risen from 31 to 66 civilians killed,” he added.The ADF is a Ugandan Islamist group that operates on both sides of the porous border. Marcel Paluku, president of a local civil society group, said all of the victims including women were killed with machetes. The number of people taken hostage remains unknown.Officials suspect the attack was in retaliation for a recent bombing campaign by joint Congolese and Ugandan forces that began on Sunday.In recent years, ADF attacks have intensified along the border with Uganda and have spread toward Goma, the main city in eastern Congo, as well as the neighbouring Ituri province. Rights groups and the United Nations have accused the ADF of killing hundreds of people and abducting many more, including large numbers of children.