KBS has found that a presumed weather balloon from North Korea entered South Korean airspace for a few hours on Sunday.

A senior military official said on Monday that the soldiers of a frontline unit in Yeoncheon County, Gyeonggi Province spotted the two-meter balloon at around 6:30 p.m. on Sunday, using a Thermal Observation Device.

The balloon flew at an altitude low enough for the soldiers to clearly identify it when it entered South Korea’s airspace.

The Joint Chiefs of Staff(JCS), which reportedly received an immediate briefing, instructed the frontline unit to simply keep a close eye on the balloon after assessing that it was a weather balloon, without giving further orders.

The balloon was later spotted by frontline units along the eastern front and reportedly left South Korea’s airspace in the direction of the East Sea after a few hours.

Meanwhile, the defense ministry said on Monday that a Chinese surveillance balloon that the U.S. shot down last Saturday over its airspace is not believed to have passed through South Korea’s airspace.