More than 100 Russian skinheads have attacked a music festival in central Russia, reports say.
At least 10 people were injured while attending the Tornado festival in Miass, in Russia's Chelyabinsk region.
The skinheads were reported to have been armed with truncheons and sticks when they launched their attack on the event, attended by some 3,000 people.
Russia's Itar-Tas news agency said police later arrested 15 people. No motive was immediately apparent.
"The detainees are being interrogated and the police are searching for their accomplices," a police official told the news agency.
Russia has an active far-right wing and racist community, and there have been several high-profile hate crimes and racially motivated murders in recent years.
Hate crimes increased sharply in the early 1990s following the collapse of the Soviet Union.
Skinhead groups began targeting people of foreign appearance such as Central Asians, residents of the Caucasus or Africans.
However, there are no suggestions yet as to why the skinheads chose to attack the festival in Miass, some 900 miles (1,400km) east of Moscow.
Many of Russia's top rock acts were said to be performing at the festival.