A man killed in a collision between a farm tractor with a trailer and a car has been identified as 45-year-old Craig Moffat from Petrolia, Ont.

The driver of the farm tractor, a 51-year-old male also from Petrolia, was not injured in the collision.

Lambton County OPP say the crash occurred in the eastbound lane of Petrolia Line between Mandaumin Road and Fairweather Road, west of Petrolia around 5:30 a.m. Friday.

Investigators say a Volkswagen struck the back of a farm tractor with a trailer. It was dark at the time of the collision, and they can't say at this point if there were working lights on the back of the farm equipment.

Lambton OPP Const. Todd Monaghan says "It's very early in the investigation, so we need some time to get through things before we know what exactly took place."

The investigation into the cause of the collision continues.

Provincial police say five people have been killed in four separate crashes this week in Middlesex, South Bruce, Elgin and Lambton County.

Two of the fatalities involved collisions with farm vehicles and police are reminding drivers to be alert on rural roads during the harvest season.

Middlesex County OPP Sgt. Dave Rektor says "It's important that motorists, especially those who aren't familiar with rural Ontario are aware that these farm machineries are big and they take up a lot of room on the roads, so it is very difficult for the farmers to see the vehicles behind them."

Drivers should slow down, ensure the operator on the farm equipment can see them and check that the way is clear before passing.