VILNIUS, Lithuania (AP) — Lithuania’s government on Tuesday declared a national emergency over security risks posed by balloons from Russia-allied Belarus that have violated its airspace in recent weeks.

Tensions between Lithuania and Belarus have escalated after meteorological balloons from Belarus forced Lithuania to repeatedly shut down its main airport in the past weeks, leaving thousands of people stranded.

In a statement, the government cited “national security interests” and “the danger” to human life, property and the environment from the balloons that have carried “contraband” from the former Soviet neighbor — actions some consider a form of hybrid warfare.

The announcement followed a Cabinet meeting of the Baltic state, which is a NATO member and strong backer of Ukraine in its fight against the Russian forces who launched a full-scale invasion in February 2022.

“The emergency was declared because of disruptions to civil aviation and because of national security concerns. There is a need for closer coordination between the institutions,” Interior Minister Vladislavas Kondratovičius told the meeting.

Kondratovičius said the emergency measures would be narrowly targeted.

While the balloons are used to smuggle cigarettes into Lithuania, officials in Vilnius see their numbers and trajectories as deliberate acts of disruption orchestrated by Belarus.

Europe overall has been on high alert after drone intrusions into NATO’s airspace reached an unprecedented scale in September and the Russian invasion of Ukraine nears its fourth year.