A medium-range ballistic missile fired Wednesday by North Korea flew about 1,000 kilometers (620 miles) and landed near Japan’s territorial waters, Seoul and Tokyo officials said, one of the longest flights by a North Korean missile.

The U.S. Strategic Command said North Korea fired two presumed Rodong missiles simultaneously, not just one. The command said initial indications were that one of the missiles exploded immediately after launch, while the second was tracked over North Korea and into the Sea of Japan.

North Korea has recently claimed a series of technical breakthroughs in its goal of developing a long-range nuclear missile capable of reaching the continental U.S. South Korean defense officials say North Korea doesn’t yet have such a weapon, but some civilian experts believe the North has the technology to mount warheads on shorter-range Rodong and Scud missiles that can strike South Korea and Japan.

According to the South Korean and Japanese announcements, one suspected Rodong missile lifted off from the North’s western Hwanghae province and flew across the country before falling in waters between the Korean Peninsula and Japan. Seoul’s Joint Chiefs of Staff said in a statement that it “strongly condemns” the missile launch because it explicitly shows the North’s intentions of being able to launch missile attacks on South Korea and neighboring countries.