Giant anteaters in Brazil have killed two hunters in separate incidents, raising concerns about the animals' loss of habitat and the growing risk of dangerous encounters with people, researchers say.

The long-nosed, hairy mammals are not typically aggressive toward people and are considered a vulnerable species by the International Union for the Conservation of Nature (IUCN).

A one-month-old anteater rides on her mother's back at a zoo in Colombia. Credit:AP

However, they have poor vision and if frightened, may defend themselves with long front claws that are as long as pocketknives.

The case studies of two fatal attacks - in 2010 and 2012 - by giant anteaters were described in the journal Wilderness & Environmental Medicine.