Lithuanian authorities temporarily closed the airspace over Vilnius on Thursday evening after balloons were detected flying toward the airport near the capital.

The airspace was shut for roughly two and a half hours from 8:10 p.m. to 10:43 p.m. local time, Vilnius airport announced in a social media post. 

According to regional media, it marked the sixth time this month that air traffic has had to be halted in the country. At least two flights headed to Vilnius were forced to return to their departure airports on Thursday evening.

Belarus has repeatedly launched such balloons, ostensibly to smuggle cigarettes across its border with Lithuania. The stunts have drawn international outrage and caused Lithuania to close its border with its unruly eastern neighbor for a month until Nov. 30.

Both European Commission President Ursula von der Leyen and European Council President António Costa condemned Belarus’ actions on Monday night, calling them a “hybrid threat.” 

Lithuanian Prime Minister Inga Ruginienė said Oct. 27 that her country intends to permanently close its border with Belarus and shoot down any balloons entering Lithuanian airspace.

Belarusian leader Alexander Lukashenko subsequently called Lithuania’s decision to close the border “absurd” and “a crazy gamble.”