The Belarus Defence Ministry is protesting to the military attache of the Lithuanian embassy over a breach of Belarusian airspace and is awaiting proof to claims that an Air Force helicopter crossed into Lithuanian territory, the ministry said in a statement.
The Belarusian Defence Ministry said Monday that Lithuania had attempted to breach the country's airspace.
According to the ministry's Telegram account, the attempt, coming from Lithuania, was detected on Sunday at about 7:30 p.m. (16:30 GMT) near the village of Volkovschina in the north of the country.
"A monitoring device with eight balloons and anti-state symbols was launched from the neighbouring territory," the ministry said.
The Foreign Ministry is planning to send a letter of protest to Vilnius.
Mass opposition protests broke out across Belarus following a presidential election on 9 August that ended with Lukashenko declaring that he'd won a sixth term, citing election officials who said that he'd won over 80 percent of the vote, despite exit polls indicating far different figures. The opposition insists that its key contender, Svetlana Tikhanovskaya, won the election.