More than fifty people were killed in a passenger bus fire on Thursday in Kazakhstan as it traveled along a major highway.

The dead, believed to be immigrant workers from a neighboring Uzbekistan, were on a 1,370 mile highway linking Shymkent in southern Kazakhstan and Samara in Russia.

Both drivers were confirmed to be among the dead.

"According to preliminary information, there were 57 people -- all Uzbek citizens -- on the bus and of them 52 passengers have died, while five managed to get out on their own," Aktilek Kenes, a spokesman for the Aktobe regional emergency situations department, said.

Doctors and psychologists were at the scene of the fire and two hotlines were reportedly set up for the victims' families.

The route is commonly used by Uzbek migrant laborers traveling to construction sites in Russia.

No cause for the fire was given, however, regional authorities said that most of the 200 vehicle fires in 2017 were attributed to electrical problems.