MEXICO City prosecutors say they are considering criminal charges against the owner of a dog that dragged a toddler off the street and killed him.

Prosecutors say the boy aged 1 year, 8 months was walking down a street with his mother on the city's southern outskirts when a boxer stuck its head through a fence, seized the child and pulled it into the yard where there were two other boxers and a pit bull.

Together, they killed the child, though the dog owner tried to pull the boy away.

Prosecutors said late on Tuesday the dogs have been taken to a city animal-control facility to be examined to determine whether they represent a continuing danger. They say the owner might face charges of criminal negligence.