GENEVA -- The United Nations said Friday that a new video from Syria circulating on the Internet that appears to show anti-government fighters kicking and summarily executing a group of frightened soldiers or militiamen could, if verified, represent evidence of a war crime to prosecute the perpetrators.
The video, which first appeared Thursday, generated widespread attention internationally and provoked debate among insurgents and their sympathizers inside Syria. The video also illustrated what rights activists called a distressing trend of atrocities committed by both sides in the 20-month-old conflict.
"It looks very likely that this is a war crime, another one," Rupert Colville, spokesman for the U.N. high commissioner for human rights, told journalists in Geneva, where the commission has its headquarters.
U.N. investigators had already collected evidence of war crimes and crimes against humanity by government and rebel forces that could support prosecutions of those responsible by national or international tribunals, Mr. Colville said. The new video, assuming its authenticity were proved, could be part of that evidence, he added. "There should be no illusion that accountability will follow," he said.
Thousands of videos depicting violence and combat in Syria have been posted on the Internet since the conflict began, mostly by anti-government activists aiming to vilify behavior of the Syrian military and a pro-government militia known as the shabiha. Many videos cannot be independently corroborated, and experts are cautious about drawing conclusions from footage that could have been digitally fabricated or altered.
But the videos are often one of the few ways to obtain information and assess the conflict's course in a country where outside media coverage is severely restricted and dangerous. YouTube footage of weapons in the conflict, for example, has revealed the Syrian air force dropping widely outlawed cluster-bomb munitions as well as insurgent use of smuggled shoulder-fired, heat-seeking missiles.
The video purporting to show extrajudicial killings of loyalist soldiers appeared to have been made at the Hamcho military checkpoint in Saraqib, a town in Idlib province in northern Syria that has been a scene of particularly brutal fighting.
In the video, captors force 10 prisoners, some pleading for their lives, to lie next to or atop one another. The anti-government fighters, whose precise identities or affiliations were unclear, yell "Allah Akhbar!" or "God is great!" A few even parade before the camera as others kick and herd the prisoners into a pile before shooting them from multiple directions.
Ann Harrison, deputy director of Amnesty International's Middle East and North Africa program, said the video demonstrated an "utter disregard for international humanitarian law by the armed group in question."
A decree in July by the International Committee of the Red Cross said Syria was engrossed in a civil war, subject to the Geneva convention on treatment of war victims. Under that change, the execution of a soldier not in combat and with no means of protection is considered a war crime.
The video from Saraqib provoked a certain amount of protest within Syria itself, with some activists saying the killings did not represent the values that inspired their revolution against four decades of repression by the family of President Bashar Assad.
"We don't want those who are liberating us from killers to resemble them and take on their values," Saraqib activist Iyas Kadouni wrote on his Facebook page. Despite the death and pain caused by pro-Assad soldiers, he wrote: "We are asking for a change for the better and to liberate the country from murderers. I'm not being insensitive about what we've all been feeling because of the innocent blood that has been spilled, but this is not how we obtain our rights."
Mr. Kadouni said he had received emailed death threats in response to his Facebook comment, warning him that he was "playing with fire."
Some rebel military commanders said such incidents were inevitable given the tensions of warfare. "I cannot stop these angry fighters," said one commander in Saraqib reached by Skype. "How can I control a fighter who lost a brother or father in front of his own eyes?"
He also said the executions may have reflected what he described as a logistics issue -- the fighters have enough trouble housing and feeding themselves without trying to provide for prisoners. Several weeks ago, they simply released 60 prisoners for this reason, he said, but they inevitably find themselves fighting the same men again.
Commanders not directly involved in the fighting said the world had to take into consideration that Syria had not been respecting global standards on issues such as prisoners since the Assad family's ascent to power, if not since their independence after World War II.
"We are a people who have been oppressed for 60 years," said Abu Thabet, the nickname for a Free Syrian Army fighter in Aleppo.
"There is a lot of repressed tension inside people," he said. "Is it possible for a population that has been living in complete ignorance and corruption for 60 years to reach the highest level of awareness within two years?"