Seoul, Sep 8 (DPA) South Korea Tuesday demanded an apology from North Korea for what it said was the unannounced release of water from a dam that created a wave of water that swept away six people in the South.

About 40 million tonnes of water was released Sunday from the dam on the Imjin River located 40 km north of the inter-Korean border, said South Korea, whose flood alert system also failed.

Three bodies of campers have been found in the Imjin while the remaining three people remained missing.

Seoul demanded a fuller explanation of the incident from Pyongyang, which said Monday that it had released the water because of a sudden high water level at the dam while also promising to provide timely warnings to South Korea in the future. It failed to mention the deaths or apologise for the incident.

The Unification Ministry in Seoul called the explanation insufficient.

“With regard to the loss of our citizens’ lives, our government demands a sufficient explanation from the North’s responsible authorities and an apology,” the ministry said.

Unannounced water discharges from North Korean dams have caused flooding and damage in South Korea since 2000 when the North began building the structures, but Sunday’s discharge was the first to cause deaths.

The water release, which occurred after it had not rained in the area for days, came at a time of cautiously warming ties between the neighbours.

After more than a year of rising tensions between Asia’s fourth-largest economy and the Stalinist North, Pyongyang made a series of conciliatory gestures last month, clearing the way for the resumption of reunions of families separated by the 1950-53 Korean War and relaxing restrictions on traffic over the heavily militarized Korean border.

It also announced it would allow South Korean tourists to visit the country again and sent its first envoys to Seoul to meet with President Lee Myung Bak since Lee took office at the beginning of last year. North Korea also released several detained South Koreans, including a manager at the Kaesong industrial park who criticised the North Korean regime