South Korea says its air force repeatedly fired warning shots at a Russian jet that twice violated its territorial airspace on Tuesday.
The defence ministry said three Russian jets were accompanying two Chinese military planes when one of them made the encroachment, the first time a Russian aircraft has done so.
South Korean fighter jets were scrambled to respond and, after they fired warning shots, the Russian jet left the area. But it returned and violated the South Korean airspace again later on Tuesday, a ministry official said. He said the South Korean fighter jets fired warning shots again.