The woman was residing in a house close to the spot on the national highway, where the tanker overturned after hitting a divider and exploded triggering a fire which spread to nearby houses and shops in the area, police said.
Thirty-two people suffered burns of which the condition of 13 was stated to be critical and four persons have been put on ventilator.
The injured had been admitted to Kannur Pariyaram Medical College hospital and other nearby hospitals.
Fire and Rescue units from neighbouring districts were summoned to fight the raging fire which was brought under control after several hours, sources said.
Over 15 houses, 12 shops and some vehicles, were destroyed in the fire.
Chief Minister Oommen Chandy and Health Minister V S Sivakumar are expected to visit the accident site today, sources said.
Kerala Agriculture Minister, K P Mohanan, who visited the area, promised all help from government side.
