(CNN) —
Warplanes from four countries faced off Tuesday in a chaotic and unprecedented confrontation above a small, disputed island off the coast of South Korea and Japan.

South Korea’s Joint Chiefs of Staff issued a statement claiming they had fired more than 300 warning shots at a Russian A-50 command and control military aircraft early Tuesday morning after it had twice violated the country’s airspace, the first such incident between the countries.

Moscow furiously denied Seoul’s account of the encounter, claiming that South Korean military jets had dangerously intercepted two of its bombers during a planned flight over neutral waters.

But in a statement Tuesday afternoon, Japan’s Ministry of Defense backed up South Korea’s claims, saying the A-50 had flown over the islands and that Tokyo had scrambled fighters to intercept.

In a further complication, both South Korea and Japan said that two Chinese H-6 bombers had joined the Russian military aircraft on sorties through the region as well.