The latest drone incursion came as Ukraine attacked the major Russian oil port of Primorsk on the Gulf of Finland.Image: Ruuti Kotkanoja / Yle, Mapcreator, OpenStreetMapYle News3.5. 10:59Updated 3.5. 12:33An unmanned aerial vehicle is suspected of violating Finnish airspace in southeast Finland, the Ministry of Defence said on Sunday. It added that "Finland is currently not facing an immediate military threat".The Air Force observed a drone flying toward Russia in the Virolahti area near the border on Sunday morning. Virolahti is Finland's southeasternmost municipality.The drone's model or origin has not been identified. Officials said it had left Finnish airspace.The case is being investigated by the Finnish Border Guard, which will provide more information as the investigation progresses.The Finnish Border Guard is investigating the latest drone airspace incursion (file photo). Image: Markus Bergfors / YleAt the request of the Air Force, regional air traffic control established a temporary aviation restriction area over a nearby maritime district between about 2am and 8am Sunday. The Ministry of Defence said this was intended to "enable a better situational picture and safe repellence of potentially stray drones" while minimising the risks to civilians.Earlier this spring, four Ukrainian drones were found in southeast Finland following Kyiv's attacks on Russian oil ports along the Gulf of Finland.Russia's biggest Baltic oil port set ablazeUkrainian drones attacked Russia’s Baltic Sea port of Primorsk on Sunday, temporarily setting it on fire, local governor Alexander Drozdenko said on the Telegram messaging app, as Kyiv launched a wave of strikes on targets across the country.He claimed that Russian air defences shot down more than 60 drones overnight over the Leningrad region, which includes the city of St Petersburg. There was no oil spill following the attack on Primorsk, and the fire was extinguished, he added.Primorsk is Russia's biggest oil-loading port on the Baltic Sea. Ukraine struck it with drones last September and again in March, causing significant damage.Ukrainian forces also struck two shadow fleet tankers in waters at the entrance to the Russian Black Sea port of Novorossiysk, Ukraine’s President Volodymyr Zelenskiy said on Sunday. Other Russian regions also reported drone attacks on Saturday and Sunday, Reuters reported.Estonia and Latvia issued public SMS warnings of an air threat overnight. Finland has not yet launched such an alert system.Yle reporter woken up by fighter jetsYle journalist Mikko Rita, who was on Tammio Island in the Hamina archipelago off Finland's southeast coast, awoke to the sound of fighter jets early Sunday.Rita heard several fighter jets flying for about an hour and a half after 4 a.m. He also heard two loud bangs that shook the windows of the cabin."Two clear, loud bangs were accompanied by a pressure wave that shook the windows of the cottage," Rita said.According to Rita, the sounds came every few minutes, and the first boom was especially loud.Rita woke up to fighter jets flying overhead, went outside and saw a fighter jet flying from land to sea."For maybe an hour and a half from then on, there were constant overflights about every 5-10 minutes," Rita said.3 May, 11:41am: Added MoD statement about no military threat, Black Sea attacks, Estonia and Latvia alerts.3 May, 12:32pm: Added map.