Lithuania's government will keep the country's two border crossings with Belarus closed for the next month after balloons used to smuggle cigarettes across the frontier brought disruption to the capital's airport.

Russian jets violated NATO airspace over Lithuania for 18 seconds during suspected refueling exercise. Nation's president calls it a breach of international law amid tensions.

Moscow denied an incursion into Lithuanian airspace after Prime Minister Inga Ruginiene said two military aircraft were spotted.

Russia has dismissed accusations by NATO member Lithuania that its aircraft violated its airspace. Lithuania said that at around 6 p.m. Thursday, a Russian Sukhoi Su-30 fighter jet and an Ilyushin Il-78 refueling tanker flew around 700 meters into its airspace from Russia's neighboring Kaliningrad region for 18 seconds before turning back.

This is a blatant breach of international law and territorial integrity of Lithuania,” a NATO-member country, Gitanas Nausėda said.

The encroachment comes after several alleged Russian airspace violations in Estonia, Poland, Romania and Denmark

Lithuanian President Gitanas Nausėda said Thursday that Russian military aircraft violated Lithuania’s airspace, calling the incursion a blatant breach of the country’s sovereignty and international law.

NATO member Lithuania said two Russian military aircraft entered its airspace on Thursday for about 18 seconds, prompting a formal protest and a reaction from NATO forces, while Russia denied the incident.