Members of a Russian motorcycle club known for its allegiance to President Vladimir Putin are touring the Balkans, the volatile European region where Moscow wants to expand its influence.

About 20 bikers from the Night Wolves club entered the Serb-controlled region of Bosnia from Serbia on Tuesday.

The group says it wants to study the history and heritage of Russia in the Balkans.

Bosnian officials have alleged the tour is aimed at intimidating non-Serbs in a country that was split by a bloody ethnic war during the 1990s.

The leaders of the Night Wolves had been banned from entering Bosnia, but could have crossed the border at a Serb-controlled checkpoint.

Serbia is officially seeking European Union membership, but has strong ties with Russian.