Monday declared day of mourning in Russia
Flags will fly at half mast, TV will not show light entertainment programs, and Orthodox services throughout the country will commemorate the victims.
More than 170 bodies have been recovered in the Krasnodar region after a flash flood on Saturday morning. More than 5,000 houses in four towns were hit by the flood. The death toll is likely to rise, as rescue workers remove more rubble.
Also on Saturday, a bus carrying Russian pilgrims crashed in Northern Ukraine, killing 14 and injuring another 29. All of the dead were women.
The bus flipped over on a motorway after a suspected driving error, and fell into a ditch.
Many of the victims either died through injuries while the bus was turning in the air, or were flattened by it when it hit the ground.
The Russian driver has been arrested by Ukrainian police, pending a criminal investigation.
Federal and regional authorities have promised $50,000 in compensation to relatives of each of the fatal victims of the crash.
The bodies have already been returned. Three pilgrims remain in hospital in serious condition.
The last national day of mourning happened almost exactly a year ago, when the riverboat Bulgaria sank in the river Volga, drowning more than a hundred passengers.