Update: Russian soldier arrested, suspected of killing 5 Ukrainian soldiers, 1 civilian in Kharkiv Oblast

Editor's Note: This story has been updated to include the most recent developments.

A Russian soldier suspected of killing five Ukrainian soldiers and one civilian was arrested in Kharkiv on Oct. 14, the Kharkiv Regional Prosecutor's Office reported.

Previously, Ukrainian media reported that a Russian prisoner of war (POW) escaped from captivity and killed five Ukrainian service members in Kharkiv Oblast on Oct. 13. Prosecutors confirmed that an investigation was underway and authorities were searching for the attacker.

The detained suspect is a 36-year-old Russian citizen from St. Petersburg serving in the Second Battalion of Russia's 1009th motorized rifle regiment, the Kharkiv Regional Prosecutor's Office said after the arrest.

According to the prosecutor's office, investigators believe the suspect may have been involved in Russian sabotage and reconnaissance operations. The report did not identify the individual as a POW, but said he was wearing civilian clothes at the time of his capture.

Investigators also believe the man may have shot and killed a civilian in addition to the murders of five Ukrainian soldiers.

The suspect is alleged to have seen a man fishing in the village of Tsyrkuny, some 16 kilometers (10 miles) from the Russian border, and shot him for fear of exposure. An autopsy revealed a gunshot wound to the head, the prosecutor's office said.  

The gunman then made his way to the village of Momotove, outside the regional capital, where he allegedly shot and killed five members of the Ukrainian military. The suspect was eventually arrested in Kharkiv.

Earlier on Oct. 14, multiple media outlets reported that five Ukrainian military personnel had been murdered in Kharkiv Oblast the previous day.

Around 4:00 p.m., a man in civilian clothing approached a building housing members of the 72nd Separate Mechanized Brigade, opened fire, and first killed one Ukrainian service member, before entering the house and killing four others, according to Glavkom.

A source in the military command in the Kharkiv region told BBC Ukraine that the suspected attacker was a Russian prisoner of war.

The Regional Prosecutor's Office confirmed an investigation was underway, but did not identify any suspects as Russian POWs.

The prosecutor's office said investigators were examining several possible motives, including whether the attacker may have been linked to a Russian sabotage and reconnaissance group.

The brigade shared a statement, saying that "On October 13, a tragic event occurred in the territory of Kharkiv region, as a result of which servicemen of the 72nd separate mechanized brigade named after the Black Zaporozhians died."

"According to preliminary information, persons who are likely citizens of the Russian Federation may have been involved in the incident," it added.

In total, the shooting lasted for about two hours, Glavkom said, while BBC Ukraine added that residents called the local police station at 04:20 p.m. about the incident. Another service member was injured in a neighboring village, according to Glavkom.

Glavkom said that two servicemen of the Russian armed forces fled captivity in Kharkiv Oblast.

During the search for the suspect, BBC Ukraine reported that the attacker was a man with a height of 160-170 cm, a lean physique, with dark hair and a unkempt beard, wearing dark blue jeans, a long-sleeved black jacket, and a grey backpack, and carrying a machine gun.

On Oct. 6, Ukraine's Coordination Headquarters for the Treatment of Prisoners of War said that Ukraine took 858 more Russian servicemen into captivity than Ukrainians were taken into Russian captivity, an average 107 per month.

Since mid-2023, the group said, Ukraine has taken more prisoners than Russia. The Ukrainian military provides bonuses for taking Russian soldiers as prisoners, as each Russian soldier might be an opportunity to exchange Ukrainian service members or civilians in Russian captivity, it added.

Ukraine and Russia exchange prisoners of war, one of the few remaining areas of direct humanitarian cooperation between the two countries amid Russia's full-scale invasion.

Ukraine and Russia have also continued repatriating the bodies of fallen soldiers despite a broader diplomatic process that has largely stalled.