Lithuania on Thursday accused Belarus of violating its airspace with a military fighter plane, an incident coinciding with the Belarussian prime minister's visit to the Baltic state.
The Vilnius foreign ministry said the MiG-29 warplane flew over the border village of Pogarenda for a couple of minutes Wednesday before turning back to Belarus.
The ministry served the Belarus embassy with a protest note requesting full details on the episode and efforts to prevent a recurrence, it said in a statement.
Belarus premier Mikhail Myasnikovich arrived in Lithuania Wednesday for a two-day visit during which he met with his counterpart Algirdas Butkevicius.
The Lithuanian premier said Myasnikovich had expressed hope for "closer ties" with the EU over their dinner, adding that he expected smoother relations to come.
The statement came after months of increased tensions over the so-called "teddy bear" stunt when Swedish activists flew a plane via Lithuania to parachute teddy bears with pro-democracy messages into Belarus last July.
Lithuania and its fellow Baltic states Latvia and Estonia lack enough aircraft to police their own skies, so other NATO members take turns patrolling them from a base in Lithuania.
The trio joined NATO and the EU in 2004.