A Russian Premier League match between Dynamo Moscow and champion Zenit St. Petersburg was abandoned over the weekend after Dynamo keeper Anton Shunin suffered an eye injury from firecrackers thrown by fans.
Late in the first half with Dynamo leading 1-0 on Saturday, the referee stopped the match after one of the missiles, thrown by Zenit supporters, landed near Shunin, injuring his eyes.
Shunin was diagnosed with chemical burns to his cornea in both eyes and some hearing loss in his right ear, Dynamo said on its website, and the 25-year-old Russia international was told to rest for at least 10 days.
"Something had landed near my feet," Shunin said. "I looked down and at that moment the petard blew up into my face. Right now I have some problems with my vision and hearing."
Police detained 53 people, including a Zenit supporter accused of throwing the firecracker that injured Shunin.
"The stadium has video cameras, so we hope to identify him," a police spokesman told Interfax.
Zenit, which won the last two domestic league titles and is backed by Gazprom, threatened to pull out of the championship in case of "unfair penalty."
"I don't understand why Dynamo tries to make us the guilty party," Zenit general director Maxim Mitrofanov told reporters. "I know that our shareholders and sponsors would be very unhappy if we were treated unfairly. In that case, we will consider pulling out of the Russian championship."
Local media reported that some 30 Zenit fans had attacked Dynamo supporters before the match in the Moscow suburb of Khimki.
It was far from ideal preparation for Zenit, which hosts Spanish side Malaga in the Champions League Group C match on Wednesday.
Zenit, which trailed league leaders CSKA Moscow by three points before Saturday's matches, could be handed a 3-0 defeat as well as a hefty fine from the Russian Football Association. Dynamo was in 10th place, 18 points off the pace midway through the season.
It was the latest in a series of violent incidents in Russian football.
Last month, a group of Dynamo fans in camouflage shot at players using paintball rifles at the club's training ground.
The fans had been angry with some of Dynamo's foreign players, warning them to boost their performances or pay the consequences.