MOSCOW -- At least 15 people are dead after a dam at a small Siberian gold mine collapsed and water flooded two workers' dormitories on Saturday.

The Emergencies Ministry also said seven people were unaccounted for, Russian news reports said. The regional health ministry said 16 people were injured.

The dam had not been registered or approved for use by Rostechnadzor, Russia's agency for technological and ecological oversight, the Interfax news agency cited the agency as saying.

The collapse during heavy rain occurred around 6 a.m. (2300 GMT Saturday) near the village of Shchetinkino in the Krasnoyarsk region about 3,400 kilometers (2,100 miles) east of Moscow.

"The hydrotechnical structure was built in a makeshift way, as I surmise, in violation of all conceivable and inconceivable standards," said Yuri Lapshin, chairman of the Krasnoyarsk regional government, according to state news agency RIA-Novosti.

The country's Investigative Committee said it has opened a criminal investigation on possible charges of violation of workplace safety regulations.

Rescue workers suspended their search for survivors after nightfall but were to resume Sunday. About 80 people were believed to be living in the dormitories.