Chinese airlines that normally fly over Russia were rerouted via Finland on Sunday. That followed Ukrainian drone strikes that damaged an oil pipeline near the Baltic port of Primorsk, between the Finnish border and St Petersburg.

Air traffic in the St Petersburg area was suspended early Sunday, with the city's Pulkovo airport closed for several hours.

Due to the airspace closure, Chinese passenger carriers that usually fly south of St Petersburg over the Gulf of Finland to Central Europe were rerouted via Finnish airspace.

For example, several planes arriving from Shanghai crossed Finland’s eastern border near Joensuu and continued across Finnish airspace en route to Central Europe.

Planes bound for St Petersburg's Pulkovo Airport were stuck in a holding pattern east of the city, waiting for the airport to reopen. Dozens of flights were delayed or cancelled. In recent weeks, several Russian airliners have landed at Helsinki Airport due to Ukrainian drone attacks.

Finnair's Asian routes have not been routed over Russian airspace since shortly after Russia's full-scale invasion of Ukraine more than four years.

Coast Guard begins live-fire drills

Leningrad Region Governor Aleksandr Drozdenko said on Sunday morning that air defence systems had shot down 19 drones in the Leningrad Region. A section of an oil pipeline ruptured in the port of Primorsk (known in Finnish as Koivisto) after being hit by falling debris, he said on Telegram, adding that the oil in the pipe caught fire without causing significant damage.

Last week several Ukrainian drones strayed into Finland, also not causing significant damage.

On Sunday, the Gulf of Finland Coast Guard began live-fire drone defence exercises at sea near the southeastern port city of Kotka.

5 April, 12.55pm: Added background details.