At least 15 gold miners were killed when a dam collapsed, flooding a mining encampment in a remote part of Siberia, officials have said.

Heavy rains weakened the dam and water broke through, sweeping away several cabins where the miners lived, about 100 miles south of the city of Krasnoyarsk.

President Vladimir Putin ordered all necessary measures to be taken to help those affected, identify the cause of the disaster and prevent any impact on a nearby residential area, Interfax quoted Kremlin spokesman Dmitry Peskov as saying.

Russia is one of the world’s top gold producers, most of it coming from large professional industrial mines. However, alluvial mining, where the gold is in a stream bed rather than an underground seam, still contributes some of the country’s output.

Alluvial (or artisanal) gold mining in Russia is usually small-scale, but is still conducted by officially registered firms, which are supposed to abide by health and safety rules.

Krasnoyarsk officials said water released by the dam partially flooded two dormitories of the rotational camp in which 74 people lived, adding that 13 people were still missing.

A Russian investigative committee said it had launched a criminal investigation into violation of safety rules at the gold mining spot, while local authorities said the collapsed dam was not registered by official bodies.

Interfax said the miners were part of the Siberian privately held company Sibzoloto, which unites several artisanal mining teams.

Sibzoloto was not immediately available for comment. The company produced about three tonnes of gold in 2018, Sergei Kashuba, the head of Russia’s Gold Industrialists’ Union, a non-government producers’ lobby group, said. Sibzoloto is not a member of the union, he added.

Russia produced 314 tonnes of gold in 2018.