The wall of a major dam in a part of southern Ukraine that Moscow controls collapsed Tuesday after a reported explosion, sending water gushing downriver and prompting dire warnings of ecological disaster as both sides in the war ordered residents to evacuate.

The dam collapse has triggered floods, endangering Europe’s largest nuclear power plant and threatening drinking water supplies.

KYIV, Ukraine -- Ukraine on Tuesday accused Russian forces of blowing up a major dam in a part of southern Ukraine they control, alerting residents further along the Dnipro River to evacuate and warning of flooding downstream.

Hundreds of people were evacuated from settlements along the southern stretch of Ukraine's Dnipro river on Tuesday after water burst through the breached Nova Kakhovka dam, submerging streets and town squares.

A torrent of water burst through a huge dam on the Dnipro River that separates Russian and Ukrainian forces in southern Ukraine on Tuesday, flooding a swathe of the war zone and forcing villagers to flee.

Flooding will make it harder for Ukrainian troops to reach Russian-occupied areas in Kherson. If reservoir levels drop too much, over 1 million would lose water.