North Korea said on Monday that it test-fired two strategic cruise missiles from a submarine on Sunday.

The North’s official Korean Central News Agency(KCNA) said an “underwater launch drill” was conducted early Sunday morning, with an 8.24 Yongung submarine launching the missiles from Kyongpo Bay in the East Sea.

The bay administratively belongs to Hongwon County, South Hamgyong Province and is close to Sinpo, where the North bases its submarines.

The KCNA claimed that the missiles struck a target in the East Sea after flying a one-thousand-500-kilometer distance along a figure-eight flightpath.

It said the drill confirmed the reliability of the North’s arms system and assessed the submarine units’ underwater-to-surface offensive operation readiness, calling the units another integral part of the regime’s nuclear deterrence.

It said the drill reasserted the military’s unchanged stance on controlling and managing the current situation with overwhelming force, adding that the “anti-republic military activities” by the U.S. and the South are becoming more conspicuous.