Two Russian MiG-31 fighter jets are suspected of violating Finnish airspace in the Gulf of Finland off the southern coast on Thursday morning, the Ministry of Defence has stated in a press release.

The suspected violation occurred at around 9:40am near the city of Porvoo and lasted for about two minutes, the ministry's communications chief Kristian Vakkuri told Yle. The jets are believed to have travelled about one kilometre in Finnish airspace before heading west.

The Finnish Air Force scrambled an operational reconnaissance flight in response to the suspected violation.

Finland's Border Guard has launched a preliminary investigation into the incident and will provide more information at a later date, Vakkuri added.

Last May, a Russian Mi-17 transport helicopter entered Finnish airspace twice on the same day, but the resulting investigation determined that the incidents were not considered to be serious violations.