TOKYO — North Korea tested a railway-borne missile system on the previous day, the state-run Korean Central News Agency reported Thursday, a day after Japan and South Korea said the North launched two ballistic missiles into waters.

“The railway-borne missile regiment took part in the drill with a mission to strike the target area 800 km away from its location after moving to the central mountainous area at dawn on Sept. 15,” the report said.

“The test firing drill took place for the purpose of confirming the practicality of the railway-borne missile system deployed for action for the first time, of judging the combat readiness and capability of performing firepower duty of the newly-organized regiment all of a sudden and of attaining proficiency in the action procedures in case of fighting an actual war,” it said.

The missiles accurately struck the target in the East Sea (Sea of Japan) in the drill guided by Pak Jong-chon, member of the Presidium of the Political Bureau and secretary of the Central Committee of the Workers' Party of Korea, according to the report.

North Korean leader Kim Jong-un did not oversee the test. The country “organized a railway-borne missile regiment to increase the capability of dealing an intensive multi-concurrent blow at the forces posing threats to us at a time of conducting necessary military operations and to markedly improve the capability for more positively coping with various sorts of threats,” the news agency added.

Wednesday's test came after Pyongyang said Monday it test-fired a new type of long-range cruise missile over the weekend. Under the UN Security Council resolutions, North Korea is banned from all ballistic missile activity.

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 North Korean launches came the same day that South Korea tested a submarine-launched ballistic missile (SLBM), becoming the first country without nuclear weapons to develop such a system.

The two Koreas have been in an increasingly heated arms race, with both sides unveiling new, more capable missiles and other weapons.

The flurry of tests on the Korean peninsula come as Australia announced it will acquire its first fleet of highly prized nuclear-powered submarines as part of a historic new defense pact with the US and Britain.

The tests by nuclear-armed North Korea drew international condemnation and concern, however, with the United States saying it violated UN Security Council resolutions and posed a threat to Pyongyang’s neighbors.

“Rail mobile missiles are a relatively cheap and reliable option for countries seeking to improve the survivability of their nuclear forces,” Adam Mount, a senior fellow at the Federation of American Scientists, said on Twitter. “Russia did it. The US considered it. It makes a ton of sense for North Korea.” — Agencies