This file photo, released by Korean Central News Agency Oct. 23, shows a hypersonic projectile launched by North Korea in flight the previous day. Yonhap

North Korea fired multiple close-range ballistic missiles (CRBMs) toward the Yellow Sea on Tuesday, South Korea's military said, amid speculation that Chinese President Xi Jinping may visit North Korea soon.

The Joint Chiefs of Staff (JCS) said it detected the missiles launched from the Jongju area of North Phyongan Province at around 1 p.m.

CRBMs refer to ballistic missiles that have a relatively short range of less than 300 kilometers.

"We have stepped up surveillance and monitoring in preparation for possible additional launches and are closely sharing related information with the United States and Japan while maintaining a full readiness posture," the JCS said.