VILNIUS, Lithuania (AP) — Lithuanian authorities said Tuesday they had arrested 21 people allegedly connected to a criminal network that smuggled cigarettes using specially equipped weather balloons from Russia-allied Belarus which have violated the Baltic country’s airspace in recent weeks.

Investigators conducted more than 80 searches, seizing cigarettes with Belarusian excise stamps, SIM cards, communication and tracking signal jammers and firearms among other things, the Lithuanian general prosecutor’s office said in a statement. Luxury cars and valuable property were also confiscated.

Lithuania earlier this month declared a national emergency over security risks posed by the meteorological balloons sent from Belarus.

The balloons forced Lithuania to repeatedly shut down its main airport, stranding thousands of people, and led to the closure of border crossings between the two countries, as Europe remains on alert over previous intrusions into NATO airspace during the war in Ukraine.

Tuesday’s operation involved more than 140 officers from the Lithuanian Criminal Police Bureau, Vilnius police and special anti-terrorism units.

The prosecutor’s office said in a statement the alleged network was “characterized by a very strict conspiracy and distribution of roles, cigarette smuggling was carried out systematically, in a coordinated manner, under strict control of its organizers (leaders) and their trustees.”

The prosecutors allege that “the organizers may have had direct contacts with accomplices operating in the Republic of Belarus, from where, under favorable weather conditions, balloons with smuggled cigarettes were launched.”

“Using tracking (GPS) equipment and appropriate programs, the movement of the balloons was monitored, and the exact coordinates of their landing in Lithuania were transmitted to the executors,” prosecutors said. “After collecting the contraband, the latter had to deliver it to pre-agreed points or hand it over to other persons involved in the crimes.”

The Lithuanian authorities said that all 21 suspects would face charges of participating in a criminal organization, illegal handling and smuggling of excise goods and aiding another state in acting against Lithuania.