Korea border
© AFP 2017/ Ed Jones
An "unidentified object" crossed the inter-Korean border from North Korea Tuesday, Yonhap news agency reported, citing South Korean Joint Chiefs of Staff (JCS).

Yonhap reported that the object was flying across the demarcation line in the eastern province of Gangwon at around 4 p.m local time [7:00 GMT].

South Korean military fired warning shots along with a warning announcement, the media outlet added.

The situation on the Korean peninsula has aggravated over a series of missile launches and nuclear tests conducted by Pyongyang in recent months in violation of UN Security Council resolutions.

On Sunday, North Korea launched a ballistic missile, which reportedly flew some 500 kilometers (310 miles) before falling into the Sea of Japan short of reaching Japan's exclusive economic zone. This is the eighth missile launch carried out by North Korea in 2017.