Moscow: Russian border guards shot at two Japanese fishing boats which had strayed into its waters off the disputed South Kuril islands, a Russian statement said on Saturday.
Border guards in a helicopter fired warning shots on Friday and then directly at the boats when they failed to stop, the statement said.
"Since all methods to stop the ships had been tried unsuccessfully, we fired for effect," the border guards from the far eastern Sakhalin region said, adding that none of the crew members were injured.
The Japanese ships then turned back and docked at the port of Rausu, they said.
Russian television showed footage of the two ships filmed from a helicopter.
The Japanese fishermen returned safely and they later found dozens of bullet holes in the boats, Jiji Press said. Another Japanese report said the Russians fired a flare bomb before shooting at the boats.
The border guards said the ships were close to Kunashir island, the southernmost in the chain, which is controlled by Russia but claimed by Japan.
Japan and Russia have yet to sign a World War II peace treaty because they both lay claim to four islands off northern Japan seized in 1945 by Soviet troops, who expelled Japanese residents.
The disputed territory is known as the South Kurils by Russia and the Northern Territories by Japan.
In 2006, a Japanese fisherman on a crab fishing boat was killed by a stray bullet fired as a warning by Russian border guards.