NATO fighter jets have been scrambled over Europe after mystery drones entered Latvian airspace and struck an oil depot. Alliance warplanes were scrambled as the unidentified unmanned aircraft flew around 40 miles into the country, with one crashing at an oil depot in Rēzekne - a city in the east of the country. Four empty oil tanks were said to be damaged in the incident. The authorities were urgently seeking to investigate whether the drone flights were a hostile act by Russia - or Ukrainian