Finland and Ireland have announced that they will close their airspace to Russian planes, but it is not yet known when the measures will take effect.

Other countries such as Bulgaria, the Czech Republic, Estonia, Germany, Poland and the UK, have already made similar decisions.

Moscow, for its part, has also banned planes from several countries from flying over its territory, as the international media report.

Finland shares a 1,300-kilometre (800-mile) border with Russia, meaning a main westbound route from Russia will be closed.