Russia has detained three officials from the Black Sea region of Krymsk in an investigation into their handling of a flood that killed 171 people there in early July, the country's main federal investigating body has said.
Moscow has accused district officials of failing to issue public warnings about the flood wave on time, which survivors say could have saved lives.
The Russian Investigative Committee said the former head of the Krymsk district Vasily Krutko, Krymsk's mayor and the head of the local government's emergency response unit had been arrested.
One other official is also under investigation for negligence but has not been arrested, the body said.
Lack of proper warnings left many inhabitants of Krymsk, a mountain town of 57,000 that was the worst hit by the flooding, caught by surprise as water poured into their homes in the middle of the night.
The flooding destroyed thousands of homes, as well as cars, roads and the power network in the "breadbasket" Russian region.
Russian President Vladimir Putin is determined to silence any criticism he was too slow in reacting to the flooding and reinforce the image of a statesman leading a strong and well-organised country.
Any drop in his strong support in the provinces would be another concern for Mr Putin after months of protests against his 12-year rule, mainly in Russia's major cities.
