Some fans of professional baseball team the Chunichi Dragons have been caught on video chanting "Let the atomic bomb drop" at the Hiroshima Carp, Dragons officials said Thursday.

In the 20-second footage uploaded to YouTube, believed to have been taken during a game last weekend at Mazda Stadium in the city of Hiroshima, several men can be heard chanting, "Go for it. Die. Let the atomic bomb drop (on the) Carp." Hiroshima was devastated by the first U.S. atomic bombing in 1945.

(Carp-Dragons season opener at Mazda Stadium in Hiroshima on March 30)

The video was shot behind fans in blue, the Dragons' color, on the third base side.

"It is difficult to identify the fans (in the video) but we extremely regret the remarks," the Dragons said. On Wednesday, the team made an announcement before a match between the Dragons and the Yomiuri Giants at Nagoya Dome urging supporters to exercise restraint.

On Thursday, the Dragons said in a statement that the club has begun making announcements at games calling for fans not to insult teams or individuals.

"We will continue to make efforts to create an environment in which spectators can watch games with a sense of security and joy," the Dragons said.