Image copyright Lodnon Police

About 100 homes were evacuated in Canada after a car crashed into a house and caused an explosion.

The collision on Wednesday evening ruptured a gas line at the property in London, Ontario.

Minutes after first responders arrived, the house exploded in what one witness described as a "fireball", leaving nothing but an empty foundation and damaging nearby properties.

One civilian and six first responders were hurt in the incident.

No one was in the home at the time.

London Fire Chief Lori Hamer said everyone was "very lucky".

Her team was called to the scene after neighbours witnessed the car crash.

"The building blew sky high, glass coming out from other buildings," neighbour Tyler Bilyea told CTV News London. "It was a fireball."

All seven wounded people have been released from hospital except one fire fighter who is in a serious but stable condition.

Most residents have been able to return to their homes, save about a dozen homes closest to the blast that were significantly damaged during the ensuing fire.

Motorist Daniella Alexandra Leis, 23, has been charged with four counts of impaired driving causing bodily harm.