KABUL, Afghanistan — A graphic video showing Afghan security forces abusing bound and wounded bodyguards of a powerful northern militia commander arrested by the country’s government emerged on Friday, and it was likely to further stoke widespread protests over the arrest that are already in their 11th day.
The video, filmed by members of the security forces as they were detaining the militia commander from Faryab Province, Nizamuddin Qaisari, and his bodyguards, shows soldiers kicking bloodied detainees in the face and stepping on their heads while smiling and posing for the camera.
The authenticity of the video could not be confirmed, although Afghan government officials have not disputed it.
Patricia Gossman, the senior Afghanistan researcher for Human Rights Watch, said that the video showed the kind of human rights abuses that the Afghan forces had been accused of before, and that the government had failed to hold people accountable.
“The video is deeply disturbing, and indicates at the very least that the men in custody were subjected to serious abuse,” Ms. Gossman said. “It is imperative that the government carry out a transparent, impartial investigation into reports that after being beaten the men were summarily executed.”
The Afghan government has promised an investigation.
“The security and defense forces of Afghanistan, in accordance with the law, should act professionally and legally,” said Shahussain Murtazawi, a spokesman for the Afghan president, Ashraf Ghani. “Any abuse or actions against the law will undoubtedly be investigated.”
The video was also disturbing because the government has itself accused Mr. Qaisari of human rights abuses.
Mr. Qaisari was nominally a district police chief in Faryab, but he played a larger role as a commander in charge of the provincial militias of the country’s exiled vice president, Gen. Abdul Rashid Dostum. The government has also accused General Dostum of human rights abuses.
It has also claimed that Mr. Qaisari and his militia are jeopardizing military operations against the Taliban. Mr. Qaisari has released videos in which he threatened to kill senior government generals — or take over the affairs of the province — if they did not improve security in Faryab.
One senior official aware of the video filmed by the security forces said the abuses most likely happened after Mr. Qaisari was moved from the scene of his arrest, and was being loaded onto a helicopter.
During that operation, Mr. Qaisari’s guards, who were resisting arrest, clashed with the government forces, and the helicopter was fired upon, said the official, who was not authorized to speak with the press.
General Dostum — whom Mr. Ghani called a “known killer” before picking him as vice president — left for Turkey last year; a political opponent has filed a court case against him and his bodyguard, saying they abducted, tortured and sexually assaulted him.
Protesters across several provinces in the north have demanded the release of Mr. Qaisari and the return of General Dostum, who they say was marginalized by Mr. Ghani.
General Dostum’s political party has strong support among the country’s ethnic Uzbeks. It has threatened to boycott the coming parliamentary and presidential elections if its demands are not met.
Almost daily protests of different sizes have occurred across at least five northern provinces, with protesters blocking the provincial elections offices in those provinces. The road to the Aqina Port, a major trade hub with Turkmenistan, has been shut down by protesters, and the main highway to Kabul, the capital, has been intermittently blocked.
Naqibullah Fayeq, the recently appointed governor of Faryab who took charge of an office burned down by protesters, said he was trying to calm the anger as negotiations with the central government over the fate of Mr. Qaisari and the return of General Dostum continued.
Nine of Mr. Qaisari’s bodyguards detained by the government have been released, and a government delegation was in Turkey negotiating with General Dostum, Mr. Fayeq said.
The unrest comes amid a raging war with the Taliban, with Afghan security forces suffering heavy casualties in the north.
At least 36 Afghan Army soldiers were killed and 12 others were wounded in the Dasht-i Archi district of Kunduz in an overnight attack by the Taliban on Thursday, according to the district governor, Nasruddin Saadi.
Mr. Saadi said that the Taliban had begun coordinated attacks on several army posts, and that fighting had continued into the morning on Thursday.
Mujib Mashal reported from Kabul, and Najim Rahim from Mazar-i-Sharif, Afghanistan.