Eleven people, including a group of migrant workers, are dead after a horrific two-vehicle crash northeast of Stratford, Ont.

The OPP said a flatbed truck and a passenger van collided shortly before 5 p.m. Monday at Perth Road 107 and Line 47 in a rural hamlet of Hampstead.

The driver of the truck is dead, along with 10 people in the van who police say were likely migrant workers. Three people survived the crash and were rushed to hospitals in Stratford and Hamilton.

Witnesses said the southbound truck, operated by Speedy Transport, hit the side of the westbound white passenger van carrying 13 people. The impact of the crash slammed the van into the side of a nearby house.

"I've been on the job for 28 years and I've never seen anything quite like this collision tonight," OPP Insp. Steve Porter told reporters on the scene Monday night.

Porter said police don't know yet which country the workers were from. At least some of them were wearing their seatbelts and firefighters had to cut them off as they scrambled to free the victims.

Police said it's not clear whether the van obeyed a stop sign at the intersection. They are not ruling out any possible crash causes, including speed and alcohol.

The speed limit on that stretch of Perth Road 107 is 80 kilometres an hour. The weather was good and the roads were clear at the time of the crash.

CTV Southwestern Ontario reporter Meghan Furman reported that a man working in his tool shed across the street was the first witness on the scene who called 911.

The man heard a loud crash and ran outside to see the mangled van against the side of a house. He tried to speak to some moaning passengers, but there was a language barrier, Furman reported.

In a statement, Ontario Premier Dalton McGuinty offered condolences to the families of those who died "and our most sincere prayers for those taken to hospital."

He also thanked first responders for providing swift emergency care "under very difficult circumstances."

"I know Ontarians will pull together to support the victims' family and friends during this difficult time," McGuinty said.

Police will remain on the scene throughout the night, examining what's left of the vehicles and the debris strewn around. The coroner is also on scene.