CHICAGO (AP) — For the first time, red panda cubs have been born at Chicago's Lincoln Park Zoo.

The zoo announced Wednesday the two cubs were born June 26 to 5-year-old Leafa.

Curator of mammals Mark Kamhout says the cubs weight about 5 ounces each. Their genders are not yet known.

Kamhout says zoo officials are optimistic about the cubs' future, noting there are vital milestones ahead for them.

Experts say although the animals are called pandas and look like raccoons, the cubs are not related to either species. Red pandas are native to the Himalayan mountain range and are considered "vulnerable" because of habitat loss and poaching.

Zoo keepers and veterinarians are monitoring Leafa and her cubs by video. It will be months before they are viewed by the public.