Lithuania closed its capital Vilnius and second-largest city Kaunas airports on Sunday after weather balloons from Belarus entered the country's airspace, Reuters reported.
The Transport Ministry said this was the third time in October Lithuanian airports had been closed due to airspace violations from Belarus.
In recent months, European aviation, including airports in Copenhagen, Munich and the Baltic Sea region, has been repeatedly disrupted by drones and other unidentified objects.
According to the Lithuanian Transport Ministry and the National Crisis Management Center, the two airports were closed until 22:00 local time (19:00 GMT) after radar detected "dozens of balloons".
Earlier this month, Vilnius airport was temporarily closed twice due to balloons flying from Belarus carrying contraband cigarettes. Lithuanian Prime Minister Inga Ruginiene warned that the country would close its border crossings with Belarus if such incidents occurred again.