North Korea has test-fired a new guided weapons system as part of an effort to improve its smaller "tactical nukes," state-run media said Sunday, as Pyongyang continues to diversify its nuclear arsenal.

“The new-type tactical guided weapon system developed under special attention of the Party Central Committee is of great significance in drastically improving the firepower of the front-line long-range artillery units and enhancing the efficiency in the operation of tactical nukes of the DPRK and diversification of their firepower missions,” the North’s official Korean Central News Agency reported, using the acronym for the country's official name.

The South Korean military said later Sunday that it had detected the launch of two projectiles into the East Sea, also known as the Sea of Japan, on Saturday at around 6 p.m. It said the two projectiles flew about 110 kilometers at a speed of Mach 4, hitting a maximum altitude of 25 kilometers.