Drivers west of Toronto in Canada were warned to keep their car windows closed after a truck spilled crates carrying five million bees onto a road.

According to The Globe and Mail, Halton Regional Police said they received a call around 6.15am (local time) reporting the bee crates had come loose from a truck and spilled onto Guelph Line in Burlington, Ontario, just west of Toronto.

It was "quite the scene", Constable Ryan Anderson said.

"Crates were literally on the road and swarms of bees were flying around," he said.

"The initial beekeeper that was on scene was apparently stung a few times."

The scene prompted police to warn drivers to close their windows as they passed by and for pedestrians to avoid the area.

About an hour after police put out a notice on social media, several beekeepers were in touch with police offering to help.

Six or seven beekeepers eventually arrived at the scene, Anderson said.

By around 9.15am, police said most of the five million bees had been safely collected and the crates were being hauled away.

Some crates had been left behind for the uncollected bees to return to them on their own.

A colony of honeybees in summer has around 50,000 to 80,000 bees, according to the Canadian Honey Council, a national association of beekeepers.