Nineteen men, most of them foreign workers, were incinerated when a Saudi bus caught fire after crashing into a truck during a blinding sandstorm, a transport official said on Saturday.
No one escaped from the burning bus when it hit a slow-moving truck entering the road from the shoulder lane on Thursday night, an executive of the Saudi bus company SAPTCO said.
"There was a big sandstorm. Nobody saw anything," he said.
The accident took place about 30 kilometres (18 miles) east of Riyadh on the route to Dammam, said the executive, who declined to be identified.
The dead included one driver and 18 passengers, he said.
Local newspapers listed the dead passengers as including four Saudis, three Indians, five Sri Lankans, two Yemenis, two Sudanese, an Egyptian and a Bangladeshi.
The official said it was not clear why no one could escape the bus amid reports that all doors and windows in the vehicle were locked.
"The bus had hammers inside to break the glass," he said.
Newspapers said the remains of the dead were taken to forensic medicine specialists for identification.