A train smashed into a truck pulling a trailer packed with farm workers Monday morning, killing 27, South African paramedics said.

Metrorail, the company operating the commuter train, said in a statement that eyewitnesses reported seeing the truck stall at the rail crossing.

Netcare 911 spokesman Chris Botha told the South African Press Association that three people were critically injured and another three were in serious condition.

Botha said the accident happened at 7:16 a.m. just outside the Cape Town suburb of Somerset West. The truck and trailer were carrying about 30 workers, he said.

No rail commuters were injured, the rail company said. It said the crossing did not have barriers but had the legally required warning signs.

A commuter train passenger identified as Ray Weyer told South African state radio that passengers on the train heard a bang, saw smoke, descended and walked toward the nearest station.

"I saw a truck in front of the train and there were a few bodies in front of it," he said. He said the train driver, who was "in a terrible state," told the passengers he didn't know what had happened.