North Korea fired two ballistic missiles on Monday, including one that may have failed and fallen inland, South Korea's military said, with the launch Pyongyang's second in less than a week.

South Korea's Joint Chiefs of Staff said in a statement the short-range missile was fired in a northeasterly direction at around 5:05 a.m., flying about 600 kilometers from South Hwanghae Province in western North Korea, with an additional unidentified ballistic missile fired at around 5:15 a.m. flying some 120 km.

A JCS spokesperson later told reporters that it is likely the second missile flew with an abnormal trajectory, given the distance it traveled, adding it may have exploded and fallen on land.

There is a possibility that it went toward Pyongyang, a JCS official was quoted by Yonhap News Agency as saying.

The spokesperson noted the possibility that KN-23 missiles had been launched, the same type as those used by Russia to attack Ukraine. North Korea is believed to have provided the missiles to Moscow.

Japan, the United States and South Korea conducted a new multidomain trilateral military exercise called Freedom Edge last week in the East China Sea, triggering a backlash from North Korea for what it labeled the allies' "provocative military muscle-flexing."

The drills signal that three-way relations "have taken on the full-fledged appearance of Asian-version NATO," North Korea's Foreign Ministry said in a statement carried by the state-run Korean Central News Agency on Sunday.

The launch came after Pyongyang on Wednesday fired a ballistic missile toward the Sea of Japan, with state media claiming a day later a success of a test of an intermediate-range ballistic missile carrying multiple warheads.

But the South Korean military has said it apparently exploded mid-air.

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