Cancun (Mexico), Feb 2 (IANS/EFE) A Canadian tourist was seriously injured when a shark attacked her off a beach in Cancun resort city in Mexico, officials said.

The emergency management office said the 38-year-old woman was attacked Monday when she was riding a water bike with other tourists off the Park Royal Hotel.

The woman was rescued by her companions, who took her ashore and called an ambulance that took her to hospital.

Lifeguards and marine patrol officers are on alert while red warning flags have been placed along the beach to let swimmers know that a shark is in the area, officials said.