Despite an international search since yesterday, no trace has yet been found of the Polish-made An-2 civilian aircraft, the Baltic state's navy said.
"Lithuanian navy ships, air force planes and Latvian helicopters are searching the area. Nothing has been found yet," Captain-lieutenant Antanas Brencius told AFP today.
The pilots did not issue a distress signal before their aircraft disappeared over the sea.
Local media said the pilots did not report any problems when they made their last contact.
"Both pilots had over 40 years of experience," Civil Aviation Administration deputy director Alvydas Sumskas told AFP.
"The conditions were good, these men could not have made a mistake. We cannot rule out the technical fault," he said.