Up to 100 people are feared injured after a passenger train derailed in Russia's southern Volgograd region, Russian news agencies reported on Monday.
The Interfax news agency said that eight train cars had been derailed.
"Paramedics are on the scene," the emergency ministry said, adding that 324 emergency workers were involved.
Emergency helicopters were being scrambled to the scene near the Kotelnikovo station. The train was travelling from Kazan to Adler on the Black Sea.
Unverified video on Telegram showed at least four carriages derailed, some twisted, with people climbing out of one that was on its side beside the rails.
TASS cited unidentified sources in Russian law enforcement as saying that 20 people had been injured when the train collided with a Kamaz truck.

Trump says operation to reopen Strait of Hormuz will be 'paused'
Hantavirus-hit cruise ship to head to Spain after being granted permission
Russian attacks kill 27 before deadline for ceasefire proposed by Kyiv
Eight dead in fire at shopping centre west of Tehran, Iranian media say
Trump says Iran should wave the white flag of surrender
