A chess robot broke a 7-year-old boy's finger at a Russian tournament. Authorities say he broke the rules.

• A Russian robot grabbed and broke the finger of his 7-year-old opponent in Moscow last week.
• Video published by Russian news site Baza shows the boy struggling to break free from the robot.

A chess robot broke a seven-year-old boy's finger during a tournament in Moscow, Russia, last week, state media said.

The child was playing against the robot at the Moscow Open tournament on July 19, the Tass news agency reported. The agency did not report the boy's name.

The machine was finishing its move when the boy reached over the board to make his own move, prompting the robot to pinch his finger, Moscow Chess Federation President Sergey Lazarev told Tass.

A video of the incident, published on the Telegram channel of the independent Russian news site Baza, shows the boy struggling to pull his finger away for several seconds as three people rush to his aid. Once he breaks free, the boy is escorted away, the video shows.

"The robot broke the child's finger — this, of course, is bad," Lazarev told Tass. He added that the boy was able to finish the tournament in a cast the following day.

Sergey Smagin, vice-president of the Russian Chess Federation, told the Russian state news agency Ria Novosti that the robot had grabbed the boy's finger because he broke the rules.

"There are certain safety rules and the child, apparently, violated them. When he made his move, he did not realize he first had to wait," Smagin said. He added that the case was "extremely rare."

Lazarev told Tass that the robot, which the federation rented for the tournament, had previously played numerous matches without any problems.

He added that the boy's parents were considering prosecution, and that "we will communicate, figure it out and try to help [the family] in any way we can."