South Korea scrambles jets as China, Russia warplanes enter air defence zone

South Korea's military said it scrambled fighter jets as two Chinese and six Russian warplanes entered its air defence zone on Wednesday.

The two Chinese H-6 bombers repeatedly entered and left the Korea Air Defence Identification Zone (KADIZ) off South Korea's southern and northeast coasts starting at around 5:50 a.m. (2050 GMT Tuesday), Seoul's Joint Chiefs of Staff (JCS) said.

They re-entered the zone hours later from the Sea of Japan, known in South Korea as the East Sea, together with the Russian warplanes, including TU-95 bombers and SU-35 fighter jets, and left after 18 minutes in the KADIZ, the JCS said.

"Our military dispatched air force fighter jets ahead of the Chinese and Russian aircraft's entry of the KADIZ to implement tactical measures in preparation for a potential contingency," the JCS said in a statement.

The planes did not violate South Korea's airspace, it said.

An air defence zone is an area where countries demand that foreign aircraft take special steps to identify themselves. Unlike a country's airspace - the air above its territory and territorial waters - there are no international rules governing air defence zones.