A collision near Guelph Line in Milton on Friday morning saw extensive damage to several vehicles, but no serious injuries, police say.

According to the OPP around 8:15 a.m. an eastbound tractor-trailer veered across two lanes of traffic and hit the concrete center median.

The cab of the truck went over the median into the westbound lanes, while the trailer, which was carrying 30 tonnes of sand, stayed in the eastbound lanes.

Two eastbound and three westbound vehicles were struck in the crash. Another tractor-trailer was disabled after it hit debris from the collision.

Two lanes were closed in each direction immediately following the crash, causing a traffic backup as far as six kilometres in each direction.

The driver of the truck, a 48-year-old Brampton resident, was not injured.

All lanes were reopened by early afternoon.

The crash remains under investigation and anyone with information is asked to contact the OPP at 905-278-6131 or 1-888-310-1122.