MOSCOW (WTVO) — A chess match turned violent when a chess-playing robot broke the finger of its seven-year-old opponent.

The incident happened on July 19 during a match at the Moscow Open, according to The Guardian. A chess-playing robot at the event was apparently unsettled by the quick responses of the boy, according to Russian media outlets, and grabbed and broke his finger during a match.

“The robot broke the child’s finger,” said Sergey Lazarev, president of the Moscow Chess Federation. “This is of course bad.”

The robot has played many matches in the past without incident, according to Lazarev. A video of the incident from the Baza Telegram channel shows the boy’s finger being pinched by the robotic arm before a woman and three men rush in to free and usher him away.

According to Sergey Smagin, vice-president of the Russian Chess Federation, that the boy opted for a quick counter before waiting for the robot to finish its move.

“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. “This is an extremely rare case, the first I can recall.”

The boy, who Baza named as Christopher, is apparently one of the top 30 players in Moscow’s under-nine category. According to Lazarev, Christopher is in a cast and does not seem overly traumatized by the incident.

“The child played the very next day, finished the tournament, and volunteers helped to record the moves,” he said. Christopher’s parents, however, have reportedly contacted the public prosecutor’s office.

Sergey Karjakin, a Russian grandmaster, said that incident was probably due to “some kind of software error or something.” He added that “this has never happened before. There are such accidents. I wish the boy good health.”