South Korean fishermen residing in northern Gyeonggi Province lost some of their equipment after North Korea discharged large amounts of water from a dam in the North into the Imjin River that flows across the inter-Korean border into the South.

According to South Korea’s Korea Water Resources Development Corporation(K-Water), North Korea discharged hundreds of tons of water per second without prior notice from the Hwanggang Dam from late Monday to early Tuesday.

The move led to abruptly high water levels at the Gunnam Dam south of the border located near Yeoncheon County in Gyeonggi Province. K-Water officials said water flowing into the Gunnam Dam increased from 97 tons of water per second to 428 tons per second, or about fourfold.

Authorities were forced to open the flood gates at the dam and released 427 tons per second to manage the abrupt increase in water flows.

Officials were uncertain why North Korea abruptly increased its release of water, but said fishermen nearby had lost some of their nets and fishing equipment as the water swept them away.

South Korean officials speculate that the North is presumed to have suddenly released more water after the upstream of the Imjin River was hit with 100 millimeters of torrential rain on Sunday and Monday.

In September 2009, six South Korean campers were killed when North Korea released without prior notice large amounts of water on the Imjin River. During an inter-Korean meeting held after the incident, North Korea agreed to notify South Korea when it releases water from the Hwangang Dam on the Imjin River.