Edgar Rinkevics, the Latvian president, wrote on social media: “We are in close contact with our allies. The number of such incidents is increasing along the eastern flank of Nato, and we must address them collectively.”

A statement issued by the country’s defence ministry said: “Latvian airspace is part of Nato airspace.”

Bucharest condemned what it described as a “renewed violation” triggered by Moscow’s “illegal attacks” on Ukraine.

Fragments of the drone were discovered in an uninhabited area near the Romanian village of Periprava, situated across the Danube river from the Ukrainian port town of Ismail, a frequent target for Russian attacks.

Alliance members on Nato’s eastern flank have had to deal with threats posed by Russian missiles and drones on numerous occasions since Vladimir Putin launched his full-scale invasion of Ukraine in February 2022.

In November 2022, a Russian missile hit Poland, killing two people. Warsaw is also searching its territory for a Russian drone that crashed on its side of the border earlier this summer.

Russian drones have also strayed into Romanian airspace on multiple occasions during Moscow’s bombardment of Ukraine’s Danube ports.