"It is very dangerous. If a person had been in this disaster, he would have had almost no chance of survival. The trees flew downwards, under the ground," said Dmitry Zaitsev, a local Emergencies Ministry official interviewed by the channel.

Officials in Nizhegorodskaya region, on the Volga river east of Moscow, said water in the lake might have been sucked down into an underground water-course or cave system, but some villagers had more sinister explanations.