North Korea on Wednesday fired a ballistic missile from a submarine into the sea in an apparent protest against Monday's start of annual South Korea-US military drills. The missile fired from a submarine off the eastern coastal town of Sinpo flew about 310 miles, the longest flight of a North Korean submarine-launched missile, Seoul's Joint Chiefs of Staff said in a statement, per the AP. US Strategic Command said it had tracked the North Korean submarine launch of the presumed KN-11 missile over and into the Sea of Japan. North Korea fired two other missiles from submarines earlier this year, but they were believed to have exploded in midair after flying about 18 miles, according to South Korean defense officials.
The North's acquiring the ability to launch missiles from submarines would be an alarming development because missiles fired from submerged vessels are harder to detect in advance. Wednesday's launch comes two days after the US and South Korea began their 12-day Ulchi Freedom Guardian exercises, prompting North Korean threats of retaliation. The South Korean military statement said it considers the North Korean missile launch as an "armed protest" against the military drills and a challenge to peace on the Korean Peninsula. It also noted that the launch violated UN Security Council resolutions that ban any ballistic missile activities by North Korea. (More North Korea stories.)