At least 52 people were killed on Thursday after a bus caught fire in Kazakhstan, BBC reported. Rescue personnel saved five people from the burning vehicle and provided medical assistance, authorities said. The cause of the fire was not immediately clear.

The bus was on its way to the Russian city of Samara on the Volga river to Shymkent in southern Kazakhstan, AFP reported. It was carrying citizens from Uzbekistan along the route that is used to transport Uzbek workers to and from Russia, where they work at construction sites.

The bus was carrying 55 passengers and two drivers were on board, AFP quoted the interior minister’s emergency department as saying. Footage of the fire showed black smoke and flames billowing from the vehicle that was completely charred.