"Two Tu-95 strategic bombers of Russia's aerospace forces carried out a planned flight in the airspace above the neutral waters of the Sea of Japan," the defence ministry said in a statement.

It also denied that the South Korean planes fired warning shots.

Moscow said two South Korean jets on Tuesday approached the Russian aircraft near the easternmost islets of Dokdo, disputed islands controlled by the South but claimed by Japan where they are known as Takeshima.

The South Korean aircraft carried out "unprofessional manoeuvres" by crossing the Russian jets' flight path and "threatening their safety," the ministry said, adding that the South Korean crews did not contact their Russian counterparts.

Russia said its bombers did not veer off course and were more than 25 kilometers (15 miles) away from the islands.

"It was not the first time that South Korean pilots tried to unsuccessfully interfere with the flights of the Russian aviation forces above the neutral waters of the Sea of Japan," the ministry said in a statement.

Officials in South Korea said it was the first time a Russian plane had violated South Korean airspace.

South Korea's Air Force scrambled fighter jets and fired warning shots, an official at the Joint Chiefs of Staff told AFP.

But Moscow said that there was no "warning fire" from South Korea otherwise the Russian jets would have retaliated.

"Had the Russian pilots felt under threat the response would not have been long in coming," the statement said.