A large truck carrying concrete and asphalt rubble smashed into a passenger bus near Moscow, cutting the bus in two and killing 18 people.
Russia's Emergency Services Ministry reported the increased death toll Saturday. Originally, the toll was reported at 14. About 25 people were injured.
The crash took place overnight near a small village on the outskirts of Moscow.
The Kamaz truck overturned when it hit the bus, a local government official said, and most of its load - 12 cubic meters of broken pieces of concrete and asphalt rubble - fell onto the wreckage of the bus.
Authorities say the drivers of both vehicles survived the crash and are being treated at a hospital.