Longueuil police were left to explain Thursday why one of its officers pulled out his sidearm and fired at a car.

Two officers were walking through the intersection of Hemard Ave. and Pare St. at around 8:30 p.m. Wednesday when a car went through a stop sign and barrelled toward them, police said.

One officer pulled out his gun and fired at the car, sending a bullet through a door and missing the driver.

"All of a sudden the car started to accelerate in their direction," said Longueuil police spokesman Marc David. "When the car got close enough one of the officers feared for his life and fired on the vehicle."

The driver then stopped, without hitting anyone or anything, and was immediately arrested and taken to a police station for questioning.

The 56-year-old woman driver will be charged with using her car to assault someone, police said.

However, several witnesses told CTV reporter Stephane Giroux that the driver did indeed make the stop.

"I heard tire screech, and then gunshot," said witness Peter Thomas.

They also said the woman looked scared, and not like someone who was deliberately trying to run down pedestrians.

"The woman was reacting like what's going on," said a witness, who wished to remain anonymous. "She was really in shock, why am I here, why are you stopping me like that."

Before the shooting, police were in the neighbourhood because of reports of teenagers loitering on the grounds of a daycare.

After the incident the officer who fired his gun was taken to hospital and treated for shock.

Because nobody was hurt, the Internal Investigations department of the Longueuil police force will look into the matter.