ISTANBUL

North Korea on Saturday fired around 10 ballistic missiles toward the East Sea, South Korea's military said.

The Joint Chiefs of Staff said that it detected the missiles launched from the Sunan area in North Korea at around 1.20 pm (0420GMT), according to the Seoul-based Yonhap news agency.

"Our military maintains a firm readiness posture while closely sharing North Korean ballistic missile information with the U.S. and Japanese sides amid a heightened surveillance posture against additional launches," a military statement said.

Seoul denounced the missile launches as violations of UN Security Council resolutions, calling for a halt.

"The latest ballistic missile launches by North Korea constitute a provocation that violates UNSC resolutions, and we call for an immediate halt," the presidential Office of National Security said after holding an emergency security assessment meeting shortly after the missile launches.

The office also reported details of the missile launches and Seoul's countermeasures to President Lee Jae Myung.

Earlier, the Japanese Defense Ministry also confirmed that North Korea fired a suspected ballistic missile, with the projectile appearing to have already fallen.

Japanese Prime Minister Sanae Takaichi instructed her government to gather information and ensure the safety of planes and ships, according to the Kyodo news agency.

No damage in Japan has been reported so far as a result of the launch

The latest launch came as South Korea and the US conduct their annual springtime Freedom Shield military exercise.

North Korea last fired multiple short-range ballistic missiles toward the East Sea on Jan. 27, and later said it was aimed at testing a renewed large-caliber multiple rocket launcher system.

Earlier in January, Pyongyang also launched its first multiple ballistic missiles this year toward the East Sea.

In a related development, the US and South Korean and US militaries staged joint river-crossing drills in the border county of Yeoncheon on Saturday as part of the ongoing Freedom Shield military exercise.

The drills took place on the Imjin River in Yeoncheon, located about 50 kilometers (31 miles) north of Seoul, involving some 200 pieces of equipment, including KM3 amphibious bridging vehicles and ribbon bridge systems, according to the armed services.

Some 700 troops from Seoul's Capital Mechanized Infantry Division and 7th Engineer Brigade, and the US Stryker Brigade Combat Team of the 2nd Infantry Division participated in the drills.