GENEVA/KINSHASA (Reuters) - Democratic Republic of Congo must investigate credible reports of atrocities including summary executions by the armed forces, U.N. human rights chief Zeid Ra’ad al Hussein said on Monday.

United Nations High Commissioner for Human Rights Zeid Ra'ad Al Hussein addresses the Human Rights Council 26th Special Session on the human rights situation in South Sudan, Geneva, Switzerland, December 14, 2016. REUTERS/Pierre Albouy

The U.N. human rights office has documented the killings of more than 280 people since July 2016 in a flare-up in violence in Kasai Central province, where Congolese forces have been battling an uprising by the Kamuina Nsapu militia.

“There are multiple, credible allegations of massive human rights violations in Kasai, Kasai Central, Kasai Oriental and Lomami provinces, amid a sharp deterioration in security situation there, including people being targeted by soldiers for their alleged affiliation with a local militia,” Zeid said in a statement.

“It is time to stop a blunt military response that does nothing to tackle the root causes of the conflict between the government and local militias but instead targets civilians on the basis of their presumed links to the militias,” he said.

The U.N. statement followed the emergence of a video at the weekend that appeared to show Congolese troops shooting dead members of the militia in the province.

The U.N. said its peacekeeping mission, MONUSCO, was not in a position to verify the origin or authenticity of the video, which showed unarmed victims being shot at point blank range as they lay bleeding on the ground.

After initially promising an investigation, the government has dismissed the video as a “montage” created by political opponents based in Brussels.

On Monday, government spokesman Lambert Mende said it was up to foreign countries accusing the army of having committed exactions to prove their cases.

“The government calls on its partners to cease promoting condescending and/or deliberately malicious attitudes toward the institutions of DRC that work to consolidate the rule of law,” Mende said.

The United States, France and the European Union all called for an investigation on Monday, and Zeid added his voice, saying the government must launch an independent and transparent probe and hold those responsible to account.