By Jussi Rosendahl and Tuomas Forsell

HELSINKI (Reuters)–Finland is becoming increasingly worried about what it sees as Russian propaganda against it, including Russian questioning about the legality of its 1917 independence.

The country shares a 1,340 km (833 mile) border and a difficult and bloody history with Russia, of which it was once a part. Moscow's annexation of Crimea in 2014 and saber-rattling in the Baltic Sea have raised security concerns in the militarily neutral European Union country.

Earlier this month, Finland and Estonia both accused Russian fighter jets of violating their airspace. Russia has also started moving nuclear-capable missiles into its Kaliningrad enclave bordering Poland and Lithuania.

Sitting in his office in the government palace–built for Russia's Grand Duchy of Finland–Markku Mantila leads a network of officials who monitor attempts to influence the country.

He says Finland is facing intensifying media attacks led by Kremlin.

"We believe this aggressive influencing from Russia aims at creating distrust between leaders and citizens, and to have us make decisions harmful to ourselves," he said. "It also aims to make citizens suspicious about the European Union, and to warn Finland over not joining NATO."

Finland won independence during Russia's revolution of 1917 but nearly lost it fighting the Soviet Union in World War Two. It kept close to the West economically and politically during the Cold War but avoided confrontation with Moscow.

Mantila, who is also the head of government communications, says Russian media last month reported on "cold-blooded" Finnish authorities taking custody of children from a Russian family living in Finland "due to their nationality."

The Finnish government denied the reports, while declining to comment on an individual case due to the legal procedure. However, the story has been replicated hundreds of times in Russia over the past few weeks.

A report by Kremlin-led NTV said "even the locals call Finland a land of ruthless and irrational child terror."

PLAQUE HIT WITH AX

Mantila, showing on his laptop what he said were false news pictures, skewed authority statements, and pro-Kremlin online discussions, said his network has verified around 20 cases of clear information operations against Finland from the past few years, and around 30 "very likely" such operations.

"There is a systematic lying campaign going on … It is not a question of bad journalism, I believe it is controlled from the center," he said.

Kremlin and Russian foreign ministry officials were not immediately available for a comment.

Foreign Minister Timo Soini has also acknowledged the alleged propaganda, saying the government was countering false information with facts.

"All states engage in propaganda, authoritarian states even more so," he told Reuters.

Some of the incidents have taken aim at Finland's independence and at its historical figures.

In June, a university in St Petersburg put up a plaque commemorating Carl Gustaf Mannerheim, Finland's most famous military officer and former president, who had served in the Tsar's army but later led Finnish armed forces in World War Two.

The plaque quickly became a target for protesters who have called Mannerheim–regarded in Finland as a symbol of the country's struggle against the Soviet Union–a murderer and ruthless Nazi collaborator.

"The plaque's been shot at, hit with an ax, and doused in red paint several times," Mantila said, noting that Finland had nothing to do with the plaque project in the first place.

Mantila said he believed the whole episode was a follow-up to earlier reports that suggested that Lenin's Bolshevik administration had no right to accept Finland's independence.

Finland celebrates its hundred years of independence next year, also the anniversary of the Bolshevik revolution.