STORY: Footage showed people rescuing dogs unable to escape the rising waters and the impact of the dam breach on wildlife.

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

Ukraine is investigating the blast at a major hydroelectric dam in the south of the country as a war crime and as possible criminal environmental destruction, or "ecocide," the office of its prosecutor general said on Tuesday.