The missiles fired by North Korea on Wednesday were a test of a new "railway-borne missile system" designed as a potential counter-strike to any forces that threaten the country, state news agency KCNA reported Thursday.
The missiles flew 800 kilometers (497 miles) before striking a target in the sea off North Korea's east coast, KCNA said.
On Wednesday, South Korean and Japanese authorities said they had detected the launch of two ballistic missiles from North Korea, just days after it tested a cruise missile that analysts said could have nuclear capabilities.