Stockholm: Swedish authorities have urged local governments around the country to step up contingency planning for a future war amid growing tensions with Russia in the Nordic and Baltic region, an official said on Friday.

This went out to municipalities in a letter earlier this week, Svante Werger, head of information at the Civil Contingencies Agency, told Reuters.

Russia's annexation of Crimea and the conflict in eastern Ukraine have worried Sweden and its neighbours and Swedish Defence Minister Peter Hultqvist said last month that the situation had continued to deteriorate.

"Planning for the threat of war has in practice, to a large extent, been absent since 2000," Werger said. "The demands are different now and the requirements will be tightened."

Stockholm decided last year to beef up civil defence capabilities and the letter to municipalities was part of this effort, he said.

This will include city officials participating in drills with the military, ensuring secure communications and checking the provision of emergency shelters, the agency said in the letter.

Sweden, which is not a NATO member, is in the process of upgrading its military, including sharply increased spending and reinstating troops to the Baltic island of Gotland.