North Korea released water from its border dam without warning this week after heavy rain hit its southern territory, a practice Seoul warns is a safety risk for people living downstream. 

The partial water release from North Korea’s Hwanggang Dam was detected through satellite imagery, South Korea’s Environment Ministry said in a press release Monday.

The water release is believed to have been carried out in response to heavy rain forecast for North Korea’s Imjin River basin between Monday and Tuesday, following an earlier spell of rain from Friday and Saturday, the ministry said.

South Korea’s Han River Flood Control