A Russian official has said a military jet’s intrusion into South Korean territorial airspace was not intentional, according to Seoul’s presidential office.
The official expressed “deep regret” to the defence ministry and blamed a technical glitch, South Korea said.
However Russia has not officially commented. Earlier it furiously denied entering South Korean airspace.
Tuesday’s incident caused alarm across the region.
Russia’s defence ministry had earlier said its plane was taking part in a joint air patrol by Russian and Chinese warplanes over the Sea of Japan and the East China Sea – the first ever air patrol between the two countries.
China’s defence ministry has also denied any of the planes had entered the territorial air space of any country.
But South Korea’s Blue House said in a briefing on Wednesday that Russia had now said the violation was unintended and that it would immediately launch an investigation into the case.
“Moscow said if the aircraft flew according to an initially planned route, this incident would not have occurred,” spokesman Yoon Do-han told reporters.
What happened on Tuesday?
The alleged incursion happened over the disputed Dokdo/Takeshima islands, which are occupied by South Korea but also claimed by Japan.
South Korea’s military said that in total three Russian and two Chinese military aircraft entered the Korea Air Defence Identification Zone (KADIZ) on Tuesday morning.
A separate A-50 Russian warplane also violated its territorial airspace twice, it said, before leaving.
South Korea says its jets fired flares and machine-gun warning shots when the Russian plane intruded. It also deployed F-15 and F-16 planes to intercept it.
Japan has protested both to Russia and South Korea over the incident.
Russian and Chinese bombers and reconnaissance planes have occasionally entered the zone in recent years, but this is the first incident of its kind between Russia and South Korea.
Russia’s defence ministry initially denied any airspace violation, and said it did not recognise South Korea’s Air Defence Identification Zone (KADIZ).
Russia also accused the South Korean pilots of “hooliganism in the air”, saying that the patrol had been more than 25km from the Dokdo/Takeshima islands.
Lt Gen Kobylash said Russia had complained to South Korea about its crews’ “illegal and dangerous actions”.
How has Japan responded?
The government in Tokyo lodged a complaint against both Russia and South Korea.
Because it claims sovereignty over the islands, Japan’s government said that Russia had violated its airspace.
It also said that South Korea’s response had been extremely regrettable.
Japan’s Chief Cabinet Secretary Yoshihide Suga said: “In light of Japan’s stance regarding sovereignty over Takeshima, the South Korean military aircraft’s having carried out warning shots is totally unacceptable and extremely regrettable.”
An alliance to give Washington nightmares
This first “joint air patrol” involving Russian and Chinese long-range aircraft in the Asia Pacific region, sends a powerful signal of the developing military relationship between Moscow and Beijing. This still falls short of a formal alliance but their joint exercises are larger and more sophisticated.
In turn this is a reflection of the ever closer economic and diplomatic ties between the two countries who, though they still have points of tension, are drawing ever closer together. They broadly share a similar world view, hostile to Western liberal democracy, eager to promote an alternative model, protective of their own national sovereignty, and often willing to ride rough-shod over that of others.
This poses a huge challenge for US strategy. The nightmare in Washington is an ever closer relationship between an assertive, but declining Russia, and a rising China, which looks set to overtake the US as a technological and economic power in the years ahead.
What are air defence zones?
An air defence identification zone (ADIZ) is an airspace which a country seeks to monitor on grounds of national security. Overseas aircraft should identify themselves before entering an air defence zone.
An ADIZ usually extends well beyond national airspace to allow for sufficient warning of a potential threat.
But ADIZs are not governed by international law and the self-defined boundaries can be disputed or overlap with other countries’ claims, which may lead to violations. This is the case in the East China Sea region, where South Korea, China and Japan all have overlapping ADIZs.
In this case, South Korea says Russia went beyond its ADIZ and into the territorial airspace surrounding the islands.
But other nations do not recognise South Korea’s claim of sovereignty.