Clashes between pro-Russian supporters and opponents occurred in the centre of the Bulgarian capital on Friday ahead of the arrival of the procession of the “Night Wolves” motorcycle club, which is known for its close ties with Russian President Vladimir Putin.

There were no serious injuries as the police intervened immediately and separated the groups.

Tensions were running high before the arrival, with the situation further exacerbated after Thursday's clashes in Burgas between Ukrainians protesting the arrival of the bikers and “Night Wolves” supporters from nationalist formations.

Following, Thursday's clashes in Burgas, four people will appear before the court on charges of hooliganism.

Sofia mayor Yordanka Fandakova has requested heightened police presence due to the procession of the bikers, with police and gendarmerie having sealed off areas through which the bikers will pass.

The bikers arrived in Sofia in the early afternoon and were welcomed at the northern entrance of the Saint Alexander Nevsky cathedral in the centre of the Bulgarian capital.

Each of the rival groups numbered around 200 people, but with the arrival of the bikers the number of their opponents diminished.

The “Night Wolves” were greeted with the Russian anthem played through a loudspeaker brought to the square. The square was lined with icons and a priest awaited the arrival of the bikers, who are later to visit the Russian church.

Supporters of the bikers could be seen waving Russian and Soviet flags as well as images of Putin, while their opponents carried EU, NATO and Ukrainian flags.