The ruling Grand National Party is blasting North Korea for what it says was Pyongyang’s opening of its Hwanggang Dam and discharge of water southward. The resulting flood has left at least three South Koreans dead and three more missing in the Imjin River near the inter-Korean border.

GNP floor leader Ahn Sang-soo criticized the North for apparently discharging water without notice and for its lack of concern for any South Koreans who may have been near the river, calling the incident an “inhumane provocation.”

He said the North must discard empty rhetoric on brotherhood with South Korea and instead show sincerity in dealing with inter-Korean affairs.

GNP lawmaker Gong Sung-jin urged the government to hold officials responsible for such contingencies accountable for the damage, saying that the government’s initial handling of the incident was inappropriate.

Main opposition Democratic Party Chairman Chung Sye-kyun expressed condolences to the families of victims, saying the incident resulted from a lack of communication between the two Koreas. He suggested the government pursue an inter-Korean agreement to prevent similar incidents.

Minor opposition Liberty Forward Party head Lee Hoi-chang called the incident “North Korea’s water attack.” He urged countermeasures to protect against such incidents, such as a warning system alerting the public of any extreme changes in water levels.

Seoul suspects North Korea opened a dam on its Hwang River and discharged 40 million tons of water southward on Sunday.