Three days after testing an ICBM, North Korea fired another ballistic missile into the sea off the east coast of the Korean peninsula, according to Seoul sources. “Our military has detected a short-range missile” that was launched at 11:05 a.m. (local time, 03:05 a.m. CET) from North Pyongan province, South Korea’s general staff said. Japan’s Defense Ministry confirmed that a “possible ballistic missile” had been launched by North Korea.

South Korea’s General Staff said “our military maintains full preparedness in close cooperation with the US.” Japan’s Coast Guard warned ships of what “appears to be a ballistic missile launched by North Korea.” The bullet seems to have “already crashed,” it said.

The military tensions on the Korean peninsula have recently increased drastically. The communist leadership in Pyongyang has repeatedly threatened a military escalation in the region. In the face of North Korea’s ongoing provocations, South Korea and the United States have increased their defense cooperation.

On Monday, the US and South Korea started their largest joint military exercises in five years. They described the 10-day “Freedom Shield” maneuver as a response to the “changing security environment” in the region following North Korea’s increased aggression in recent months. The exercises should continue until Wednesday.

North Korea had strongly criticized the maneuver. Shortly before the start of the exercises and on Tuesday, Pyongyang had already tested several missiles. North Korea then fired a Hwasong-17 ICBM on Wednesday. This is Pyongyang’s largest and most powerful projectile. It was the second ICBM test this year.

UN resolutions ban North Korea from testing ballistic missiles of any range. Depending on the design, such missiles can be equipped with a nuclear warhead. Last year, ruler Kim Jong-un declared his internationally isolated country an “irreversible nuclear power”. Earlier this month, he also ordered the military to step up maneuvers in preparation for “real war.”

According to state media, hundreds of thousands of young North Koreans have volunteered for military service to fight against the “US imperialists”. On Friday alone, more than 800,000 youth league officials and students across the country signed up to join the people’s army, the official KCNA news agency reported on Saturday. Photos in the state-run newspaper Rodong Sinmun showed long lines of young North Koreans at what appeared to be a construction site.