North Korean balloon briefly spotted over South Korea, Seoul says

South Korea's military said on Monday it had tracked a North Korean balloon over its territory, but determined it did not pose a threat.

The balloon briefly entered South Korean airspace on Sunday, the Ministry of Defense said in a statement, adding it in response had taken unspecified "measures".

The craft left South Korean airspace a few hours later and officials believe it was a weather balloon not one intended for spying activities, Yonhap news agency reported, citing an unnamed official.

The report comes after the United States shot down a suspected Chinese surveillance balloon, further straining relations with Beijing which said the craft was a civilian airship that had accidentally strayed into U.S. airspace.

Tensions have risen between the two Koreas, with the North conducting a record number of missile tests last year, and the South joining with U.S. allies in military shows of force.

Five North Korean drones crossed into the South on Dec. 26, including one that briefly entered a no-fly zone surrounding South Korea's presidential office, prompting South Korea's military to scramble fighter jets and helicopters.

The military was criticised for failing to bring down the drones, which flew over the South for hours.