Sarnia police say hundreds of people were assisted by several Canadian agencies after high winds caused problems for those involved in the Port Huron Float Down on the St. Clair River and turned it into an international incident.

Police say they started to receive calls for assistance around 4 p.m. Sunday afternoon after winds at approximately 40 kilometres per hour pushed several of the floaters across to the Canadian side of the river.

The Float Down is an annual event which sees thousands of people “float down” the St. Clair River on floatation devices.

Due to the cooler weather and water many floaters needed assistance from Sarnia down through Corunna.

Sarnia police say the event poses "significant and unusual hazards" given the fast-moving current, large number of participants, lack of life jackets and challenging weather conditions.

They say it took hours for a bus service to transport about 1,500 U.S. citizens back to Michigan.

Staff Sgt. Scott Clarke told The Times Herald the float down participants were "unprepared to be stranded anywhere.It was a bit of a nightmare, but we got through it," he said. "There were long waits and long lines. They were cold and wet, but they all made it home."

The event started at Port Huron's Lighthouse Beach and was supposed to end at Chrysler Beach in Marysville.

Sarnia city workers spent several hours Monday picking up beer cans, coolers, rafts -- even picnic tables -- that washed up on the Canadian shore, said spokeswoman Katarina Ovens.

"I guess they were on the rafts," she said of the picnic tables.

Agencies involved with the assistance included Sarnia police, fire, Lambton EMS, OPP, Canada Customs and Border Agency, RCMP, Coast Guard, Sarnia Transit, and fire personnel from various chemical plants. Members of the general public also offered assistance.

U.S. citizens were helped from the water and given any necessary assistance before being transported to U.S. customs and immigration via Sarnia Transit buses.

- With files from The Associated Press