Updated 4:30 P.M. EST

A large snake that escaped from a pet store killed two young boys in Canada on Monday.

The children, who were reportedly 5 and 7-years-old, were sleeping over at a friend's apartment located above a reptile store in northern New Brunswick when the snake attacked them, Global News reports.

"The city is in shock," Deputy Mayor Ian Comeau told CBC News about the deadly attack.

The incident took place at 6:30 a.m. while the children were asleep, according to a statement by the Royal Candian Mounted Police. A preliminary report led police to believe the snake escaped its enclosure, traveled through the building's ventilation system and strangled the boys to death.

No one knows how the snake escaped from the pet store, known as Reptile Ocean in Campbellton. Initial reports said the snake was a boa constrictor, but later reports point to a 14-foot green anaconda. The snake was captured and is in RCMP possession. Autopsies will be performed on the boys' bodies on August 6 in Saint John, New Brunswick.

Not “man-eaters” by nature, green anacondas are native to tropical climates in South America. They typically eat small mammals, fish and turtles by coiling their bodies around its prey and squeezing them to death. Large anacondas, which can measure up to 29 feet long, can capture prey as large as adult white-tailed deer which are the same size as a small humans weighing up to 120 pounds.

On Reptile Ocean’s Facebook page, the company lists itself as an exotic pet store that sells fish, snakes, lizards, crocodiles and alligators. Photos of several reptiles it owns including a rat snake, woma python and corn snake – constrictor snakes that suffocate their prey.

Comeau added that Canada allowed the importation of large snakes in 2009. In an effort to control the population of several invasive snake species, the United States banned the importation of four of them last year, CNN reports. The snakes, the Burmese python, the northern and southern African pythons, and the yellow anaconda, have become serious problems in Florida.

Back in May, a college student was lauded for killing an 18-foot Burmese python with his bare hands. After the snake wrapped itself around his body, Jason Leon, 23, beheaded the 128-pound reptile in a Florida forest after he spotted it while riding his ATV.

"I would think a snake of that size could kill a very large animal," Carli Segelson, a Florida Fish and Wildlife Commission spokeswoman told NBC News. "It could kill a deer, so a person would be comparable in size to that."