South Korea says it fired warning shots after Russian military planes entered its airspace.
Fighter jets were also scrambled in response.
According to the Defence Ministry in Seoul, it's the first time an aircraft from Moscow has violated the country's territorial sky.
It is planning to summon officials from the Russian Embassy to register formal protests.
US-Iran peace talks end without agreement, delegations leave Pakistan
The US and Iran failed to reach an agreement to end their war despite marathon talks that concluded on Sunday in the Pakistani capital Islamabad, jeopardising a fragile ceasefire.
Russia, Ukraine trade accusations of ceasefire violations
Russia and Ukraine accused each other on Sunday of breaching the 32-hour ceasefire in their four-year war, reporting more than a thousand drone and shelling attacks just hours after the truce began on Saturday to mark Orthodox Easter.
At least 30 dead in stampede at Haiti’s historic Laferriere Citadel
At least 30 people were killed on Saturday in a stampede at the Laferriere Citadel in the northern countryside of Haiti, authorities said, warning that the death toll could rise.
Cyclone lashes New Zealand's North Island, hundreds evacuated
A cyclone battered New Zealand's North Island on Sunday, cutting power to thousands of residents and forcing hundreds to evacuate, as officials warned conditions would worsen through the day.
US-Iran talks pause for now, disagreements remain
Negotiations between the United States and Iran appeared to have concluded for now, Iran's government has announced early on Sunday, after a series of talks in Pakistan to end the six-week war between Washington and Tehran.
