MOSCOW – Officials have opened a criminal investigation after a circus bear attacked and injured its trainer during a performance in northern Russia.

Video of the Wednesday attack in Olonets, a town 110 miles northeast of St. Petersburg, shows the bear pushing a wheelbarrow while walking on its hind legs, then attacking the trainer, biting him and forcing him to the floor. Another trainer hurries forward and kicks the bear repeatedly.

The online news site gazeta.ru cited a witness as saying the bear then ventured into the audience area before being subdued with an electric shocker.

According to The New York Times, the 16-year-old brown bear named Yashka was the star of the Anshlag traveling circus from the city of Voronezh. The bear's handler, Ruslan Solodyuk, said the 660-pound animal was on his last tour as a performer and wasn't feeling well at the time of the attack, the paper reported.

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Solodyuk told the Russian site Daily Storm that the bear was never violent before Wednesday's attack.

The manager of the circus, Lyudmila Misnik, told Russian news media Thursday that audience members didn't turn off the flash on their cellphones, which might have provoked the bear. She also assured that both the trainer and the bear are fine.

There were no barriers between the circus ring and the audience. The Interfax news agency said the Investigative Committee has opened a criminal investigation on a charge of providing unsafe services.

Contributing: Associated Press. Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.