At least fifty-two people were killed Thursday when the bus they were travelling on caught fire in Kazakhstan, the central Asian nation’s emergency services ministry said in a statement.

“On January 18 at 10:30 am (0430 GMT), a bus caught fire … 55 passengers and two drivers were on board. Five people who managed to escape are receiving medical assistance. The rest died on the spot,” the ministry said, without elaborating on the cause of the inferno.

The route, which is about 2,200km (1,300 miles) long, is frequently used by Uzbek migrant labourers travelling to construction sites in Russia, observers said.