Unification Minister Hyun In-taek says North Korea intentionally discharged water from its Hwanggang Dam without advance notice.

Hyun made the remark at a meeting of the parliamentary foreign affairs committee on Wednesday when asked by lawmaker Song Young-son whether the discharge was deliberate.

The minister said the government is still trying to figure out what the North’s intention was.

But he stopped short of calling it a “water attack.” Hyun stressed the government will take strong measures calling for Pyongyang’s thorough explanation and apology.

The unannounced release of water caused a flash flood on the Imjin River and the death of six South Koreans on Sunday.