Lithuanian engineers and U.S. soldiers pump water from a swamp in an effort to recover a U.S. Army M88 Hercules armored vehicle near Pabrade, Lithuania, March 27, 2025. (U.S. Army Europe and Africa)

A mission to find four missing U.S. soldiers in Lithuania has been hampered by wet and muddy terrain, complicating an effort involving hundreds of personnel, U.S. Army officials said Thursday.

“We are leveraging every available U.S. and Lithuanian asset to coordinate for and provide the required resources for this effort,” U.S. Army Maj. Gen. Curtis Taylor, commander of the 1st Armored Division, said in a statement.

The soldiers were inside an M88 Hercules armored recovery vehicle when they went off course into a bog. The submerged M88 was discovered Wednesday evening during a search-and-rescue effort by American troops and Lithuanian authorities.

“The challenges presented by the water, thick mud and soft ground around the site have complicated recovery efforts and have required specialized equipment to drain water from the side and stabilize the ground,” U.S. Army Europe and Africa said.

The Army has not declared the soldiers dead, with officials saying they are still considered missing.

The soldiers, all assigned to the 1st Armored Brigade, 3rd Infantry Division out of Fort Stewart, Ga., have been missing since the early hours of Tuesday. They were on a maintenance mission to recover another U.S. Army vehicle during scheduled unit training on Lithuanian military grounds, the Army said.

The initial search took rescuers through thick forests and swampy terrain, USAREUR-AF said. U.S. and Lithuanian soldiers and law enforcement have been assisting in the effort along with military helicopters and diving teams.

Engineers at the site are working to create berms to establish a contained area from which water can be pumped and mud dredged, providing emergency personnel on site access to the vehicle, the Army said.

Lithuanian military and law enforcement personnel observe efforts to recover a U.S. Army M88 Hercules armored vehicle near Pabrade, Lithuania, March 26, 2025. (U.S. Army Europe and Africa)

Engineers and emergency workers clear mud and water in an effort to recover a U.S. Army M88 Hercules armored vehicle near Pabrade, Lithuania, March 27, 2025. (U.S. Army Europe and Africa)

“Due to the terrain, this is an incredibly complex engineering effort. The team on the ground is working to remove enough water and mud for rescue teams to safely reach, stabilize, and access the vehicle,” said Maj. Robin Bruce, a 1st Armored Division engineer.

Lithuanian and U.S. Army engineers are excavating mud from the site and making improvements to support heavy equipment needed for recovery, the Army said.

The Army said the families of the soldiers are being kept up to date on the status of the search.

“This tragic situation weighs heavily on all of us and we’re keeping the families, friends and teammates of our soldiers and recovery team in our thoughts and prayers,” Taylor said. “We want everyone to know, we will not stop until our Soldiers are found.”

The soldiers were training at a military site near the city of Pabrade, about 6 miles from Lithuania’s border with Belarus.

The 1st Armored Brigade was among the first units to deploy to Europe in the aftermath of Russia’s 2022 full-scale invasion of Ukraine.

The unit returned to the Continent in January to begin another nine-month rotation. Units within the brigade train in Lithuania, Poland and other parts of NATO’s eastern flank.