52 Uzbek migrant workers die after their moving bus bursts into flames "It’s too early to talk about the reasons for the fire," an official said

BELGRADE, Serbia -- At least 52 people died when their moving bus caught fire in Kazakhstan today in one of the region’s deadliest bus accidents in years.

All the victims are believed to be Uzbek migrant workers on their way to the city of Kazan in Russia, a Kazakh emergency ministry official told ABC News. Kazakhstan is a former Soviet republic.

Five people survived the blaze, the ministry said, which was near the village of Kalybai.

Two of the survivors suffered burns to their hands, while the others had minor injuries, emergency services officials said. Three survivors were Kazakh drivers, taking turns at the wheel, and the two others were Uzbek passengers, the officials said.

The bus burst into flames before fire quickly tore through the vehicle, killing the 52 people before they could flee after the bus stopped, an emergency ministry official said, declining to give her name.

Both Uzbekistan and Kazakhstan’s emergency services ministry said they have opened a hotline.

The incident occurred around 10:30 a.m. local time, the emergency ministry said in a statement.

The bus was traveling from the tiny town of Zibek in Kazakhstan’s southern Saragaiski region to Kazan, Russia, an 1,800-mile route often used by migrant workers heading for jobs on construction sites in Russia.

The bus, manufactured in 1989, was registered in Kazakhstan, most likely as a private transporter, Yerbolat Sakulov, a senior official in the Kazakh ministry of interior, said. “We are checking all our registries, to see if he had a transportation license,” Sakulov said.

But he provided no details on the cause of the fire. “It’s too early to talk about the reasons for the fire; it just happened this morning,” Sakulov told ABC News. “There is an investigation going on.”

Investigators suspect it was triggered by a short circuit, The Associated Press reported.

Today’s fire highlights the risk of passenger transport in the region. In October of last year, for instance, a Kazakh-registered bus with Uzbek passengers was hit by a train in Russia after it broke down on the tracks, killing 19 people aboard the bus.