NATO fighter jets were scrambled twice overnight after suspected drone incursions triggered air alerts across large parts of Lithuania, with at least one drone entering the country's airspace before flying into Latvia, officials said on Wednesday.

The first yellow alert was issued in the Vilnius and Utena regions at around 11 p.m. on Tuesday (2000 GMT) and lifted shortly after midnight. A second alert was later declared in the Alytus region before being expanded to parts of central and northern Lithuania and upgraded to red, urging residents to seek shelter.

Vilmantas Vitkauskas, head of Lithuania's National Crisis Management Centre, said three drones had initially been detected in Belarus, but none entered Lithuanian airspace during the first incident. One later entered Latvia. During the second incident, a drone was believed to have entered Lithuania from Belarus near the southern town of Druskininkai, flying north across several regions before leaving the country's airspace near Pasvalys.

Vitkauskas said NATO fighter jets detected the object but did not shoot it down, possibly because of poor weather or safety concerns. Lithuanian Prime Minister Mindaugas Sinkevicius described it as a "difficult night", saying four drones had been spotted across the region and that an attempt was made to bring down a drone above northern Lithuania. Debris from a missile fired by a NATO fighter jet was later found near Birzai.

The incidents disrupted air traffic, with Vilnius and Kaunas airports temporarily closing. Three flights at Vilnius Airport, affecting more than 400 passengers, were impacted, Vitkauskas said.

Latvia's National Armed Forces issued an airspace threat warning for several municipalities early on Wednesday, activating drone interceptors, air defence units and NATO air policing jets. Latvia ordered residents in two border regions to seek shelter on Tuesday. Estonia also issued alerts, and Finland imposed temporary restrictions on airspace and maritime activity in the eastern Gulf of Finland.

The number of drones involved and whether any crashed or were shot down remained unclear, according to officials.

The alerts came as Ukrainian drones targeted northwestern Russia, home to major Baltic Sea export facilities and an oil refinery. Moscow has accused Kyiv of using NATO airspace to launch attacks against Russian territory. Ukraine says Russian electronic jamming has forced some of its drones off course. Ukrainian military drones have previously strayed into the airspace of Finland, Estonia, Latvia and Lithuania.