Kiev, June 8 : As fears loom over an ecological catastrophe due to the breaching of a major dam in southern Ukraine, President Volodymyr Zelensky said that "Russian terrorists have detonated an environmental bomb of mass destruction". In a social media post on Wednesday, the President said: "The whole world knows about this Russian war crime, the crime of ecocide -- the deliberate destruction of the dam and other structures of the Kakhovka hydroelectric power plant by the Russian occupiers. "In fact, Russian terrorists have detonated an environmental bomb of mass destruction." The breach of the dam and the subsequent destruction of a hydro-electric power plant in the Russian-controlled Nova Kakhovka region in the early hours of Tuesday, led to mass evacuations as water levels downstream rapidly increased. Officials have said that 30 towns and villages along the river have been flooded and nearly 2,000 homes have been submerged in the city of Kherson -- the region's capital controlled by Ukraine. Of the 30 flooded towns and villages, 20 are controlled by Ukraine and 10 are occupied by Russia. Kiev and Moscow have traded accusations over the dam's destruction, without providing concrete proof that the other is culpable. It is not yet clear whether the dam was deliberately attacked or whether the breach was the result of structural failure. In his nightly address to the nation, Zelensky further said although the country's "military and special services were rescuing people and doing as much as possible, despite the shelling... But large-scale efforts are needed". He called on international organisations, such as the International Committee of the Red Cross, to immediately join the rescue operation and help people in Nova Kakhovka. Also on Wednesday, Ukraine's Prosecutor General Andrii Kostin announced that the country has "initiated proceedings over this crime, qualifying it as a violation of the laws and customs of war and ecocide. It has caused severe long-term damage to people and the environment." "The consequences are catastrophic. More than 40,000 people have been affected. Homes and infrastructure have been destroyed, land has become unsuitable for agriculture, and water supply has been disrupted in a number of regions, both in the government-controlled areas and in the territories temporarily occupied by Russia," CNN quoted Kostin as saying in an official statement. Concerns are now turning to the dangers to wildlife, farmlands, settlements and water supplies from the floodwaters and possible contamination from industrial chemicals and oil leaked from the hydropower plant into the Dnipro River. The flooding has already killed 300 animals at the Nova Kakhovka zoo, according to the Ukrainian Defence Ministry. Before its collapse, the critical Nova Kakhovka dam was the largest reservoir in Ukraine in terms of volume. It is the last of the cascade of six Soviet-era dams on the Dnipro River and supplied water for much of southeastern Ukraine and the Crimean peninsula that was annexed by Russia in 2014. /IANS