New Brunswick RCMP have launched a criminal investigation into the deaths of two young boys killed by a python that reportedly slithered through ventilation shafts after it escaped from a reptile store, though police say it's too early to determine whether charges will be laid.

Police confirmed that the store owner also resides in the upstairs apartment in Campbellton, N.B. where the two boys, aged five and seven, were found dead Monday morning.

Reptile Ocean owner Jean-Claude Savoie was hosting the two boys, aged five and seven, for a sleepover with his own son.

Savoie reportedly found the two boys and called 911, police said. His son was in another room and was unharmed, police say.

Campbellton RCMP Sgt. Alain Tremblay said police are in the first stage of a criminal investigation.

"I can tell you it's a criminal investigation right now to determine if any criminal act is responsible for the death of the two boys."

RCMP said the snake is an African rock python, as long as 4.5 metres and weighing approximately 45 kg. The non-venomous snake typically kills by constricting its victims.

The RCMP released the ages of the two boys, but have not yet identified the pair. Their mother lives nearby.

Const. Julie Rogers-Marsh said the preliminary investigation led police to believe that a python escaped its enclosure at the store sometime overnight. Initial information indicates the snake got into the ventilation system and then into the apartment upstairs.

"It's believed the two boys were strangled by the snake," she said, noting that autopsies are scheduled for tomorrow in Saint John.

Police were called to the residence on Pleasant Street at 6:30 a.m. local time.

It's not yet clear how the snake escaped, but officials now have it in their possession. Initial reports suggested the snake was a boa constrictor.

City in shock

"This is a tragedy," said Deputy Mayor Ian Comeau. "The city is in shock."

Lisa Janes is a co-owner and curator of Little Ray's Reptile Zoo, a private zoo and education program in Ontario and the Maritimes.

"We were absolutely shocked and saddened," she said Monday afternoon. "Our condolences go out to the family."

She regularly handles exotic snakes and says they can be aggressive, but it's usually for one of two reasons: "They bite because they're feeling scared or threatened, or because they smell food."

Janes said snakes don't usually see humans as food. In the New Brunswick tragedy, she said they could have been startled, or smelled something else that was a regular food source in the room.

She pointed out that more people are killed by dogs than by snakes.

Education is important to understanding and dealing with such animals, she said.

In 2009, the province of New Brunswick allowed a wider variety of snakes, lizards and other exotic pets into the province. Under the change, pet stores were then able to sell non-venomous snakes up to three metres in length.

Kevin Craig, a wildlife biologist with the province's Natural Resources department, said in a 2009 interview that pet stores pushed for the change because the province's regulations were more restrictive than other jurisdictions.

Calls to the pet store by The Canadian Press were not returned on Monday but Comeau said Reptile Ocean was licensed to operate and "everything was according to our bylaws, to the provincial guidelines."

Reptile Ocean's Facebook page was flooded with angry comments Sunday after a post saying commenters should "be ashamed of themselves" for blaming the store. It also said it would temporarily deactivate its page to "avoid further demeaning comments."

In response to the tragedy, the city of Montreal announced Sunday it is considering stiffening its laws on exotic snakes. It currently allows ownership or non-venomous snakes under three metres long.