Lithuania declared a "code red" air alert today over an unidentified flying object and told people in the north and centre of the country to go to bomb shelters for about an hour, the Lithuanian army and the local crisis management headquarters said, according to BTA.

NATO air policing jets took off while the alert lasted. The airport in Kaunas, Lithuania's second-biggest city, was closed.

The headquarters, citing the army, said the object most likely came in from Poland. The Lithuanian army is checking whether drone debris fell near the village of Juodžionys in northern Lithuania, after the object vanished from radar.

Earlier in the day, the Polish army said it was checking a possible breach of Polish airspace by an unidentified object.

Latvia also declared an air alert. The Latvian army said the cause was a "possible threat". The authorities lowered the alert to "code yellow" for some border areas with Lithuania, and about an hour after it began they said the danger had passed.

In recent months, Ukrainian drones have repeatedly strayed into the airspace of the Baltic states. Kyiv says Russian jamming systems push them off course. The incidents raise fears that the war is reaching NATO's borders.