Dozens of balloons used by smugglers to transport cigarettes from Belarus into Lithuania forced the temporary closure of Vilnius airport overnight on Tuesday to Wednesday, authorities announced.
The Lithuanian capital's airport was closed from 11:00 pm local time on Tuesday to 6:30 am on Wednesday (2000 to 0330 GMT).
The head of the National Crisis Management Centre, Vilmantas Vitkauskas, described the latest wave of balloons as "the most intense this year."
The decision to suspend flights was made "to ensure the safety of civil aviation," he was quoted as saying by the Baltic news agency BNS.
Traffic was also stopped for the same reason overnight at two land border crossings between Lithuania and Belarus, before reopening on Wednesday, the Lithuanian border guards said.
Lithuania's Prime Minister Inga Ruginiene called on the authorities in Minsk to cooperate to prevent similar incidents in the future.
She urged Belarus to adopt "a responsible approach to these incidents, irrespective of our political relations."
"It's not normal that so many balloons are crossing our border and that we have to intercept them to keep them away from our strategic sites and installations," she told reporters on Wednesday.
A similar incident previously disrupted the operation of the airport in Vilnius on October 5, when some 25 balloons crossed into Lithuanian airspace.
Similar balloons landed on Lithuanian soil, including at the airport, earlier this year and border guards have had the right to shoot them down since last year.
Smugglers use weather balloons to attach Belarusian cigarettes, to sell them in the European Union where tobacco products are more expensive.
A total of 966 balloons entered Lithuania last year and more than 500 so far this year, according to official data published earlier this month.
Neighbouring Poland has also seen more than 100 similar incidents this year, according to border police there.
Lithuania is a member of the EU and NATO. Violations of its airspace are a sensitive issue after a number of suspected Russian drones crossed into its territory from Belarus in July, including one carrying explosives.
Agence France-Presse