The missiles fired by North Korea on Wednesday were a test of a new “railway-borne missile system”, state news agency KCNA reported on Thursday.
The missiles flew 800 km (497 miles) before striking a target in the sea off North Korea's east coast, KCNA said.
On Wednesday, South Korean and Japanese authorities announced 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.
The test was conducted by a railway-borne missile regiment that had been organised earlier this year, the KCNA report said.
“The railway-borne missile system serves as an efficient counter-strike means capable of dealing a harsh multi-concurrent blow to the threat-posing forces,” said Pak Jong Chon, a North Korean Marshal and a member of the Presidium of the Politburo of the ruling Workers' Party of Korea, who oversaw the test, according to KCNA.