Pyongyang sent the balloons just days after 200 similar balloons were sent to South Korea.

According to reports, North Korea had sent them in reply to sending propaganda leaflets from South.

South Korea's Joint Chiefs of Staff (JCS) said it has detected some 720 balloons that floated across the Military Demarcation Line separating the two Koreas and fell in different parts of the country between 8 p.m. Saturday and 1 p.m. Sunday, reported Yonhap news agency.

The balloons carried various pieces of trash, such as cigarette butts, paper and plastic bags, just like the previous balloons, according to the JCS.

"About 20 to 50 balloons are moving per hour through the air and coming down in Seoul, Gyeonggi Province, North Chungcheong Province and North Gyeongsang Province," a JCS official told the South Korean news agency on the condition of anonymity.  

No injuries have been reported so far.

North Korea has been jamming GPS signals near the border since Wednesday, Yonhap news agency reported.

The two warring neighbours have been cut off from each other since the end of the Korean War in 1953 with an armistice.

Both the warring neighbours have reportedly used balloons as their propaganda tactics.

Earlier this month, a South Korea-based activist group claimed it sent 20 balloons which were carrying anti-North Korea leaflets and USB sticks containing Korean pop music and music videos across the border.

In 2020, Seoul's Parliament passed a law to criminalise the launch of anti-Pyongyang leaflets.