By Laurence Peter
The Slovak foreign ministry says it is “disturbing” that the Night Wolves – a Russian nationalist biker gang close to President Vladimir Putin – now have a base in Slovakia.
The base has old military vehicles and lies in Dolna Krupa, a village 70km (44 miles) from the capital Bratislava.
The Russian government calls it the Night Wolves’ “European headquarters”.
The bikers are under US sanctions, accused of providing military help for the pro-Russian rebels in Ukraine.
Slovak foreign ministry spokesman Peter Susko told the BBC that the Night Wolves’ activities would have to be “carefully monitored”.
“We think the influence of their members is harmful, especially in spreading their opinions that strive to rewrite history,” he said in a phone interview.
When asked to specify those controversial opinions he said “that Crimea is, was and will be Russian, that Stalin was a great hero, that Nato is a criminal organisation, etc”.
Bikers’ Slovak supporters
Slovakia is a member of both Nato and the EU. Formerly part of communist Czechoslovakia, it was an ally of Moscow during the Cold War.
A Slovak nationalist group called NV Europa, led by Jozef Hambalek, is sharing the compound with the Night Wolves.
Mr Hambalek owns the site, which was previously a pig farm, Slovak media report. Last week he threatened Radio Free Europe/Radio Liberty journalists who were filming outside the base.
The Russian bikers say they are turning the site into a World War Two museum honouring Soviet units who used motorbikes.
Speaking on Tuesday, Slovak President Andrej Kiska called the Night Wolves “a tool of the regime that has been involved in the occupation of a neighbouring country” – referring to Russia’s intervention in Ukraine.
He called the bikers’ base “a serious security risk” for Slovakia.
Mr Susko told the BBC “they claim to be a club” and “they are not a government organisation, so it’s difficult to intervene through the [Russian] embassy”.
“It’s a case of clear concern that people who express views directly contrasting with the foreign policy outlook of Slovakia are trying to organise themselves on the territory of Slovakia,” he said.