A three-month old infant was killed by its family's pet hybrid wolf-dog in the US state of Alabama, police have said.

The child died on Thursday in Chelsea, about 20 miles (32km) southwest of Birmingham, Alabama, from injuries that are suspected to have been caused by the animal.

The wolf-hybrid was euthanized at the scene by a veterinarian, the Shelby County Sheriff's office said.

The city's mayor called the death "unfortunate and tragic".

"It's been confirmed that one of our children here in Chelsea was killed by an exotic family pet and succumbed to their injuries yesterday afternoon after being taken to the hospital," said Mayor Tony Picklesimer in a statement.

Police said they were called to the home of the infant on Thursday at around 13:00 (19:00 GMT) local time, after a 911 call was placed for an animal attack.

The infant was then taken to hospital, where they were pronounced dead due to injuries sustained from the attack.

Police described the animal as a "wolf-hybrid" that was kept by the family of the infant as a pet.

They added that they continue to investigate the circumstances leading up to the child's death.

Mayor Picklesimer told BBC's US partner CBS that there were other children inside the home at the time of the incident.

A similar incident occurred in 2018, in which an eight-day-old baby died after being attacked by its family's three-year-old wolf hybrid in Virginia.

What is a wolf hybrid, and are they legal to keep as pets?

According to the International Wolf Center in Minnesota, a wolf-dog hybrid is the child of a domestic dog and a wolf that had been mating.

"These two species are interfertile, meaning that they can interbreed and produce viable offspring," the Center stated on its website.

"In other words, wolves can breed with dogs, and their offspring can produce offspring themselves."

They are often confused with wolfdogs, which are domestic dogs with higher than normal wolf ancestry, said Giselle Narvaez Rivera, a wolf curator with the International Wolf Center.

She added that wolf-dog hybrids are much less common in the US than wolfdogs.

Whether they make good pets or not has been a topic of much contention.

A few people are successful in keeping a wolf hybrid as a pet, according to the International Wolf Center, and the higher the wolf percentage is in the animal, the less likely they can be kept as a house pet.

Thousands of them are abandoned in the US every year because people purchase an animal they are not prepared to care for.

Ms Narvaez said owning a hybrid wolf-dog as a pet can be challenging because of their complex and unpredictable behaviour.

"If you are going to do it, you have to take so many things into consideration especially if you're having kids," Ms Narvaez Rivera told the BBC.

Federal law in the US classifies wolf hybrids as domestic animals, therefore making it legal to own one as a pet.

However, most US states have their own laws regulating the breeding and ownership of such animals that sometimes vary by county.

A few states, like Illinois, Michigan and New York, have made it illegal to keep a wolf hybrid as a pet.

It is not illegal to own a wolf-hybrid in Alabama, though there are rules around how they should be kept and confined.

In the UK, first-generation wolfdogs - where one parent is a wolf - require a license to own, as outlined by the Dangerous Wild Animals Act of 1976.

However, it is legal to own one as long as it is three generations away from the original parent wolf.