Two siblings were taken to hospital after being attacked separately on the same day by a dog their family was looking after.

Police in Montreal say it happened at a home in the Montreal North area.

First, a four-year-old girl received serious injuries Sunday morning when the dog grabbed her head in its mouth.

The family then locked the dog inside, but it was somehow able to escape a few hours later and charge at the girl’s seven-year-old brother, who was playing outside. He received a serious bite wound to the arm.

People who saw the attack were able to hold the dog until police and animal control officers arrived at the scene, although they reported that the dog remained aggressive and tried to attack other children.

Both children were taken to hospital with serious injuries. The boy underwent reconstructive surgery, while the girl received 16 stitches to her head.

One neighbour said she heard children screaming and saw a man with a shovel.

Police say the family was watching the dog, on behalf of a friend. It is now in the care of an animal shelter.

Paperwork identifies the dog as an American Bulldog mix. It appears to be a pit bull-type dog. Montreal lifted its ban on pit bulls and other dog breeds deemed dangerous earlier this year.

The city has been in the process of implementing a new set of animal control rules, which Mayor Valerie Plante says will not target any specific breeds of dog.

“It’s really about making sure that dog owners, animal owners, understand that they are responsible to all the population,” Plante told reporters on Monday.

The new bylaw will come into effect in July 2019. It will require dogs which have shown aggressive tendencies to be muzzled in public, kept on short leashes and examined by behavioural experts.

Plante said she was “troubled” to hear of Sunday’s attack and hoped the new animal control bylaw would prevent similar incidents.

With a report from CTV Montreal’s Cindy Sherwin