UPDATE: All eastbound and westbound lanes have now reopened. Highway 6 ramp to 401 eastbound remains closed.

A crash involving a tanker truck carrying jet fuel has forced the closure of Highway 401 in both directions near Cambridge, Ont., Ontario Provincial Police said Sunday.

Const. Robert Visconti said the truck was carrying 50,000 litres of highly flammable fuel when it rolled over shortly before 2 a.m. after colliding with another vehicle in the eastbound lanes.

The truck rolled onto its driver's side and spilled the fuel on both eastbound and westbound lanes of the highway.

The road closure is expected to last until the afternoon at the earliest as it took a while for clean up of the highly flammable liquid to begin.

"It was a logistics nightmare trying to get a company that will actually come out to clean up jet fuel," Visconti said.

But by late morning, crews were cleaning up the spill, he said.

The highway is closed between Highway 6 South and Townline Road, Visconti said.

"We initially had a much bigger closure due to safety reasons because the jet fuel is so flammable, but that has been scaled back as the cleanup progresses," Visconti said.

He said the road will likely re-open sometime Sunday afternoon.

The truck driver was taken to hospital to be treated for minor injuries, Visconti said.