MOSCOW — Torrential rain along Russia’s rugged Black Sea coast set off flash floods and landslides that killed at least 150 people, according to the Associated Press.

A storm that began Friday night dumped 11 inches of rain on the southern region of Krasnodar, forcing residents to flee their homes as floodwaters coursed down out of the hills. One of the worst-hit towns was Gelendzhik, where in recent years a lavish $1 billion palace was built in secret, apparently for the use of President Vladimir Putin. (The Kremlin denies it.)

Emergency officials said Saturday they had sent helicopters to the region to assist in rescue efforts. It was not clear whether the choppers would be able to use the three helipads that were constructed on the grounds of the heavily guarded palace.

The Russian Orthodox church has also built a new palace nearby, reportedly for its head, Patriarch Kirill.

Putin flew to the region Saturday evening, viewing the damage from a helicopter, the Associated Press reported.

In Krymsk, the water reached a reported depth of 12 feet. Mudslides have cut off roads and rail lines, isolating some children’s summer camps. Port operations in Novorossiysk have been shut down. The rain let up Saturday, and the floodwaters began to recede, but more stormy weather is forecast for Monday.