The site, near Quebec City, was under excavation in February to improve public washrooms when a backhoe turned up the remains, the Canwest News Service reported. They were left intact until the spring thaw, and details were released Tuesday.

"There is no record of a burial being done in this area -- it's a complete surprise," said bio-archeologist Vanessa Oliver-Lloyd, who works for the National Battlefields Commission.

Initial examination led Oliver-Lloyd to say she suspected the bones belonged to a male teenager and a female adult.

"I definitely don't think they were soldiers," she said.

She said the type of nails used for the caskets predated 1830-1850, and speculated they had been buried there as customs of the time didn't allow non-Catholics to buried in Catholic cemeteries.