BREAKING: 4 US soldiers dead after going missing on training mission in Lithuania: NATO

The soldiers were last seen alive on Tuesday in an armored vehicle, during tactical training exercises at a military site in eastern Lithuania. The base lies six miles from Belarus.

The Lithuanian military has not confirmed what happened, though local reports say that the four may have drowned after their M88A2 Hercules armoured vehicles became trapped in swampy conditions, reports the New York Post.

“This is still early news so we do not know the details,” Rutte said while in Warsaw on Wednesday. “This is really terrible news and our thoughts are with the families and loved ones.”

No statement has been made by the US Army on the deaths yet, but they have expressed their thanks to Lithuania’s armed forces for helping on the search and rescue mission.

“I would like to personally thank the Lithuanian Armed Forces and first responders who quickly came to our aid in our search operations,” Lt. Gen. Charles Costanza, V Corps commanding general, said in a statement. “It’s this kind of teamwork and support that exemplifies the importance of our partnership and our humanity regardless of what flags we wear on our shoulders.”