The United Nations’ special coordinator for the peace process said early Friday that he condemned the killing of a disarmed Palestinian assailant by an IDF soldier in Hebron the morning before.

“I strongly condemn yesterday’s apparent extrajudicial execution of a Palestinian assailant,” Nickolay Mladenov said in a statement. “This was a gruesome, immoral and unjust act that can only fuel more violence and escalate an already volatile situation.”

A graphic video of the incident in the West Bank city of Hebron went viral and sparked widespread criticism of the unnamed soldier’s actions, including from Prime Minister Benjamin Netanyahu and Defense Minister Moshe Ya’alon, who both said that the actions went against the “values” of Israel and its military.

The soldier, who was arrested after the video surfaced, said he shot the man because he believed he was wearing a suicide-bomber vest.

Mladenov said he welcomed Ya’alon’s condemnation, and urged Israeli authorities to “swiftly bring to justice the perpetrator who has already been detained.

“It is time,” he continued, “to stop the negative spiral of violence and to begin positive steps toward ending the occupation and bringing long-overdue peace and security to the people of Israel and Palestine.”

The soldier told military investigators he believes he acted properly in shooting the attacker in the head as he lay wounded and weaponless on the ground, Channel 10 news reported.

His lawyer, Benjamin Malka, explained that the assailant, who had just stabbed another Israeli soldier, was still “moving underneath his jacket, where he could have been hiding explosives or weapons.”

In the video, the soldier is partially blocked from view by other members of his unit when the shot is fired. However, the impact of the bullet can be seen. The Palestinian man can then be seen bleeding from the head.

(Video contains graphic images)

The video prompted the Israel Defense Forces to launch an investigation into what it said was “a very grave” incident.

IDF spokesman Brig. Gen. Moti Almoz said the soldier had been arrested and pledged that there would be a thorough investigation into the shooting. “This is not the IDF, these are not the values of the IDF and these are not the values of the Jewish people,” he said.

Ya’alon said the case would be handled “with all due severity,” saying the soldier’s apparent actions were “in utter breach of IDF values and our code of ethics in combat.”

As news of the shooting spread, Israeli lawmakers from the center-left reacted harshly, warning of the dangers of moral decline and of loose firing regulations in the military.

The Palestinian Authority, meanwhile, accused Israel of committing “a war crime,” with PA Health Minister Jawad Awwad saying the Palestinian assailant had been “executed” by soldiers, and claimed the footage was “irrefutable evidence that Israeli soldiers commit field executions.”

An IDF soldier stands near blood stains from the body of a Palestinian assailant allegedly shot in head by a soldier as he lay wounded on the ground after stabbing and injuring an Israeli soldier in Hebron on March 24, 2016. (AFP/HAZEM BADER)

An IDF soldier stands near blood stains from the body of a Palestinian assailant allegedly shot in the head by a soldier as he lay wounded on the ground after stabbing and injuring an Israeli soldier in Hebron on March 24, 2016. (AFP/Hazem Bader)

Israel has come under criticism from Europe and the United States for allegedly using excessive force in stopping Palestinian terrorists. The PA and some countries, notably Sweden, have accused Israel of extrajudicial executions — something Israel has vigorously denied.

The incident in Hebron marked the first attack since Saturday, breaking a rare calm spell amid a wave of violence in the West Bank and Israel that has raged for nearly half a year.

In the nearly six months of Palestinian terrorism and violence since October, 29 Israelis and four foreign nationals have been killed. About 190 Palestinians have also been killed, some two-thirds of them while attacking Israelis, and the rest during clashes with troops, according to the Israeli army.