South Korea scrambled multiple jets in response to its air defence identification zone (KADIZ) being allegedly violated by two Russian Tupolev Tu-142s last week.

Quoting military sources, Yonhap News Agency reported that the two Russian jets entered KADIZ four times from Jeju on Friday and remained in the air space for around an hour and thirty-nine minutes.

The South Korean aircraft, which included F-15Ks, sent warning messages in line with the military's operation manual.

No additional measures were taken as the Russian jets "clearly defined their purpose of flight".

"In communication with our side, they clearly defined their purpose of flight," the source told Yonhap.

It is believed that the Russian maritime reconnaissance and anti-submarine warfare aircraft had taken part in the Sino-Russian naval drills, held near China's Qingdao from April 29 to May 1.

Two Russian warplanes had previously violated the KADIZ in July last year. Following this, Seoul lodged a strong protest with Russia by summoning a Russian military envoy.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)