MOSCOW: Russia's state federal aviation agency will suspend flights for nine regional airlines that have not paid their debts for services, the agency said in a statement on Wednesday.

"Despite numerous requests from the federal aviation service to the management of these companies... they currently have considerable unpaid debts," Russian news agencies quoted the statement as saying.

The flight suspension will come into effect on Friday.

The companies affected by the ban include Interavia, a regional carrier which is based in Moscow's Domodedovo airport and flies to Siberia, the Far East and the Caucasus region in southwest Russia.

Another company included in the ban, Dalavia, which flies to the Far East and destinations in Asia, has already suspended flights and had its bank accounts frozen because of a separate debt investigation.