Russian police have arrested three officials in the southern Krymsk region accused of failing to warn residents of disastrous flooding earlier this month.
The former head of Krymsk district, who had already been fired for his handling of the floods, and the mayor of Krymsk town are among those held.
The floods claimed the lives of 171 people, mostly in the town of Krymsk.
The floods hit the region overnight, catching many residents unawares, and were blamed on torrential rain.
The town of Krymsk was devastated as thousands of houses were almost completely submerged by rising water.
Many residents were forced to take refuge in trees or on rooftops.
"Essentially ignoring the weather service forecasts, the suspects did not inform the population about the looming danger and did not take steps to evacuate people," spokesman for the Investigative Committee said to Russian TV, according to the AFP news agency.
The floods were the first major disaster of President Vladimir Putin's third term in office, and federal authorities have been eager to show they are heeding criticism of the official response, which has been voiced even in normally pro-government media outlets.
Russian federal authorities launched an investigation shortly after the floods into possible negligence.
Mr Putin flew to the region himself in the immediate aftermath of the floods.
Local officials had said flood warnings were given using sirens, SMS messages and loudspeakers. But many people were asleep when the floods hit and did not hear them.