Family members of two missing U.S. citizens who traveled to eastern Ukraine to fight in the Russia-Ukraine war are worried they may have gotten captured by Russians, The Telegraph reported Thursday.

Thirty-nine-year-old Alexander Drueke, from Tuscaloosa, Alabama, and 27-year-old Andy Huynh, from Hartselle, Alabama, were last heard from by their families June 8. They were posted in Kharkiv, Ukraine, on a mission and did not return, according to Reuters.

There is no confirmation from the State Department that they have been captured, Reuters reported. If they have been captured, they would be the first American prisoners of war in the conflict.

“What we know officially at this point from the State Department is that Andy and Alex are missing,” Huynh’s fiancee, Joy Black, reportedly told Reuters. “We do not have confirmation for anything beyond that. Obviously the longer the search goes the more we start to consider other scenarios.”

A comrade of the pair reportedly told The Telegraph the men had been captured “after running into a much larger Russian force during a battle” in Izbytske, which is 5 miles from the Russian border. They were part of a 10-man unit and ran into a unit of 100 Russians with tanks, he reportedly told the outlet.

Drueke and Huynh “manned an RPG7 rocket-propelled grenade launcher together,” the man reportedly added. (RELATED: ‘His Legs Were Gone’: Canadian Sniper Wali Describes Worst Day Of Fighting In Ukraine)

“Everybody took cover waiting for one of the tanks to hit the anti-tank mine, but Alex and Andy saw a BMP3 coming from another direction through the woods and realized that it would kill most of us. They opened fire and took it out with their first shot,” he said, according to the outlet.

A Russian tank then fired back and Drueke and Huynh seemed to vanish in a fog of smoke, he reportedly added, believing them to have been captured by Russians. There were no remains found of the men, and a Russian Telegram channel boasted that Russian soldiers had captured two American “mercenaries,” the man reportedly added.

Alexander Drueke and Andy Huynh, two US military veterans who have joined the #Ukrainian army have been captured by #Russian occupiers in #Kharkiv region, reports @Telegraph. pic.twitter.com/PZADAEK3i1

— NEXTA (@nexta_tv) June 16, 2022

Russian Ministry of Foreign Affairs spokeswoman Maria Zakharova said the U.S. had not contacted Russia about the two men, Reuters reported, citing Ria news agency.

Drueke is a veteran, comes from a family of veterans and spent two tours in Iraq, according to CBS42. When the war broke out, he wanted to help Ukrainians “defend democracy,” his mother said, according to the outlet.

“When Russia invaded Ukraine, Alex immediately told me he wanted to go use his skills to train Ukrainians in how to operate American weaponry,” Drueke’s mother, Bunny, said, according to the outlet. “He isn’t married, he doesn’t have kids, and he has the training and the experience. He felt it was his duty to help defend democracy, wherever needed.”

Huynh served in the Marines but had no combat experience, according to The Telegraph.

“When Andy saw this footage coming out of Ukraine he said he couldn’t sleep, couldn’t eat, was just consumed by the horror that these innocent civilians were going through,” Black said, according to Reuters.