Police in Tanzania are hunting for a truck driver who let 43 Ethiopian migrants suffocate to death inside his vehicle before dumping the bodies and abandoning survivors, officials said Wednesday.

“A manhunt is going on for the driver of the lorry that abandoned the Ethiopian immigrants by the roadside,” said Luppy Kung’alo, a Tanzanian police spokesperson.

A total of 125 people had been inside the truck on Tuesday in central Dodoma province, about 400 kilometres west of the economic capital Dar es Salaam, police said, as they updated an earlier death toll of 42.

Survivors told police that while they were locked inside the truck they had screamed to the driver to stop after several people passed out due to the lack of air, said local police chief Zelothe Stephen.

When the driver finally stopped, he ordered the migrants to dump the corpses and clean the truck, but then roared off, leaving the Ethiopians behind in a remote area.

“After they cleaned up, he got in and drove off, leaving both the bodies and the survivors,” Kung’alo said.

“People from nearby villages saw the bodies lying next to the road, and later they saw people crossing into the wilderness trying to head into a nearby village,” Stephen said.

The bodies, a number of which were already decomposing, were taken to a government hospital. Survivors have received medical treatment and are being looked after by the police.

“After we take care of their basic needs, we will hand them over to the department of immigration, which will be responsible for them,” Kung’alo said.

The migrants are believed to have left their native Ethiopia several months ago and were heading south toward Malawi, officials said.

Their likely route took them through Arusha in northern Tanzania toward the southern town of Mbeya and eventually across the border to Malawi, an interior ministry official said Wednesday.

“There have been several cases involving illegal immigrants using Tanzania as a conduit to their destinations in southern African countries, but none involving such numbers,” Kung’alo said.

Last week, the bodies of 47 Ethiopians were recovered from Lake Malawi, which forms much of the border with Tanzania, after their overcrowded boat capsized.

In December, 20 Somali immigrants were found dead in Tanzania.

The foreign ministry said at the time that an increasing number of Ethiopians and Somalis were crossing the country to make their way to South Africa, the continent’s top economy.

Hundreds of thousands of Somalis have fled the lawless Horn of Africa country since the collapse of a formal government two decades ago, while crippling drought racked both Somalia and Ethiopia last year.