The U.S. Treasury Department said the U.S. government has imposed sanctions on General Abdel Fattah al-Burhan, the head of Sudan’s military and de facto president.

He has been leading one of two sides in a 21-month civil war that has killed tens of thousands, displaced more than 12 million and pushed the country to the brink of famine.

In a brief statement, the United States accused General Burhan of “destabilizing Sudan and undermining the goal of a democratic transition.”

There had been reports of civilian killings in the central city of Wadmadani in recent days, but this was not mentioned in the statement.

Last week, Mohammed Hamdan Dagalo, the leader of a paramilitary group fighting the army, was also slapped with U.S. sanctions.

The United States accuses Dagalo’s Rapid Support Forces (RSF) of committing genocide during the conflict.

Announcing sanctions on Burhan on Thursday, Washington said troops under his command had “carried out deadly attacks on civilians,” including targeting “schools, markets and hospitals.”

The United States also claimed that the military “used food deprivation as a war tactic and routinely and deliberately denied humanitarian access.”

In the first year of the conflict, Secretary of State Antony Blinken said the military committed war crimes.

Earlier, General Burhan ordered an investigation into allegations that his troops committed widespread atrocities after retaking the Gezira state capital from paramilitary rivals.

His move comes amid widespread fears that civilians, including foreigners, have been killed following the occupation of Wad Madani.

Neighboring South Sudan said on Wednesday it had summoned Sudan’s ambassador to protest “the loss of life of innocent citizens.”

Wad Madani, 87 miles (140 kilometers) south of the capital Khartoum, was seized by SSF about a year ago. The military regained control of the area on Saturday.

The city is a strategic crossroads, connecting several states via major supply highways. It is also the closest major town to Khartoum.

A Sudanese human rights group accused the army of rampaging at Camp Taiba, about 20 kilometers away, in which at least 13 people were killed.

The United Nations humanitarian chief in Sudan, Clementine Nquita-Salami, said she was deeply concerned by reports of reprisal attacks against civilians in Jazira “based on alleged affiliation or ethnicity.”

Tom Perillo, the U.S. special envoy for Sudan, called the reports “shocking” and urged military and allied groups to investigate and hold those responsible accountable.

General Burhan said he had set up a committee to investigate the alleged killings at the Taiba camp and asked the committee to submit a report within a week.

He did not comment on the concerns raised by South Sudan or whether the investigation would focus on alleged atrocities elsewhere in Gezira.

South Sudan’s Ministry of Foreign Affairs said it had received a “comprehensive report” from the embassy in Sudan “detailing the unfortunate incident that resulted in the loss of innocent citizens of our non-combatant status”.

The military has previously accused Doctors Without Borders of hiring South Sudanese as “mercenaries” to fight on its side.

Social media videos of various incidents were widely shared online, including one showing a man in plain clothes being thrown off a bridge and then shot by a group of men.

BBC verify has confirmed that the video was filmed on the Hantub Bridge over the Blue Nile.

We matched key elements from the video, including the railings and paintings on the railings seen in the video, with previous footage shot on the bridge.

One of the men involved in the incident was carrying a Sudanese flag and wearing clothing emblazoned with the logo of the Bala Bin Malik Brigade, which has been fighting alongside Sudanese forces in Khartoum and neighboring countries.

Two other videos shot elsewhere showed the bodies of at least 30 men in civilian clothes lying on the ground next to a wall.

By matching objects seen in the video with satellite imagery, BBC verify determined that the video was filmed at a location northwest of Wad Madani, just meters from where the army appeared to ambush Médecins Sans Frontières fighters.

It was unclear how the men died or whether they were killed before their bodies were collected there.

It was also impossible to determine their identity or whether they were affiliated with any fighting party, as it is common for armed combatants to not wear uniforms.

Videos of the ambush, fierce firefight and aftermath are also circulating.

The Sudanese Armed Forces on Tuesday condemned “individual violations” in parts of Gezira state and pledged to hold those responsible accountable.

Médecins Sans Frontières itself has been accused of carrying out revenge attacks in Gezira after the defection of its commander, Abu Akela al-Kakkar, last October.

Kekar ​​took an active part in the operations that led to the military retaking control of Wadmadani.

Additional reporting by Yussuf Abdullahi, BBC Monitoring.