The search for four U.S. Army soldiers who went missing during a scheduled training exercise near Pabradė, Lithuania, has shifted from rescue to recovery mission.

The troops, assigned to the 1st Brigade, 3rd Infantry Division, out of Fort Stewart, Georgia, were last seen aboard an M88 recovery vehicle before it was found submerged in deep mud and water.

Officials said the soldiers disappeared during "scheduled tactical training" in an area near Lithuania's border with Belarus, and a search and recovery effort was underway.