Updated: Fri Oct. 30 2009 7:40:57 AM

The Canadian Press

PETERBOROUGH, Ont. — Police say an incident involving a 47-year-old Peterborough, Ont.,-area woman who suffered severe burns has been ruled "accidental."

The woman had been using an unknown flammable liquid when it ignited and caused her injuries.

She was taken to hospital in grave condition, suffering second- and third-degree burns to more than 50 per cent of her body, including her mouth and throat.

Provincial police and ambulance personnel were called to the home in a rural area east of the city about 5:15 on Thursday morning.

The unidentified woman was airlifted to the burn unit at a Buffalo, N.Y., hospital.

The Fire Marshal's office was called in to investigate.