A Russian fighter jet and a refueling aircraft briefly crossed into Lithuanian airspace from the Kaliningrad region on Thursday evening, the Lithuanian Armed Forces said. 

Lithuania’s President Gitanas Nausėda condemned what he described as “a cruel violation of international law and territorial sovereignty of Lithuania.” 

“We have to react to this,” he said on X, posting from Brussels.

The planes — which were likely conducting mid-air refueling training — penetrated about 700 meters into Lithuanian territory near the south-western town Kybartai and remained there for roughly 18 seconds before turning back.

In response, two Spanish Air Force jets deployed under NATO’s Baltic Air policing mission were scrambled to intercept and subsequently began patrolling the area.

The situation “is fully under control,” Lithuania’s Prime Minister Inga Ruginienė said in a Facebook post, adding that Lithuania’s response to the threat was appropriate.

“This incident once again demonstrates that Russia acts as a terrorist state, disregarding international law and the security of its neighbors,” she said, adding that “together with our allies, we will guard and defend every inch of our country.”