The home secretary is seeking "urgent advice" about banning American XL bully dogs as footage shows one of the animals attacking an 11-year-old girl and a man in Birmingham.
Suella Braverman has said the animals are a "clear and lethal" danger after the video of the attack in Bordesley Green emerged on the social media platform TikTok.
West Midlands Police are investigating after two men, who were bitten and left with injuries to their shoulders and arms, were taken to hospital to be treated for their injuries after the incident on Saturday.
Police have said the dog was initially taken to a vet to be checked over before being taken into secure kennels while the investigation continues.
Officers say they have spoken to the owner of the dog but there has been no arrest.
The home secretary tweeted after the video emerged: "This is appalling.
"The American XL bully is a clear and lethal danger to our communities, particularly to children.
"We can't go on like this. I have commissioned urgent advice on banning them."
The advice was commissioned last week, an adviser said, with it being the Department for Environment, Food and Rural Affairs' responsibility to add the breed to the banned list.
The girl can be heard screaming in disturbing footage of the attack as people gather around to help her. The dog then sprints across Churchill Road and lunges at a man on the forecourt of a Texaco petrol station.
Someone off camera can be heard saying "call the police" as the animal gets up on its back legs and pulls the man to the ground.
Another man then runs over with a broom and hits the dog as more people come over to help.
The man who was being attacked then gets to his feet and runs off while the dog is still chasing him.
Earlier this month two XL bully dogs were shot dead after killing 22 pregnant sheep in North Wales.
Meanwhile, Emma Whitfield, the mother of 10-year-old Jack Lis - who died after being mauled by one of the dogs in Caerphilly, South Wales - has been calling for a change in the law.
Sir John Hayes, a close ally of Ms Braverman, has been pushing in the House of Commons for a ban of the dog he has claimed is "bred to kill".
The American bully XL is closely related to the pit bull terrier, a banned breed, but is not subject to any legal restrictions itself.