A litter of rare white lion cubs was born Monday in a zoo in the Georgian capital Tbilisi.

According to the zoo, four cubs were initially born on December 10 but one died shortly afterwards. This is not rare in multiple-birth litters.

The surviving cubs, two males and one female, were separated from their mother shortly after birth. They are now being looked after 24 hours a day and are being bottle-fed by handlers.

The zoo's director said it was a very special moment. "White lions were born in Tbilisi Zoo a few days ago. It's a very important event - as any animal birth in a zoo is an important event. And especially when it's about a rare breed of an animal like the white lion," Zurab Gurielidze told Reuters TV.

"There are no white lions in nature any more. There are just some of them left in a captivity. We can view any birth like this as a contribution to restoring this rare breed," Gurielidze explained.

The parents, Samuel and Cleopatra, are the only lions of their kind at the zoo. They arrived in Georgia from South Africa in 2009 and 2010. The cubs will now spend one year in Tbilisi before a decision is made about where they are to go.

Scientists now believe that white lions, which actually vary from light yellow to bright white, are not a separate subspecies: they are a mutated version of regular sand-colored Kruger lions. Like white tigers, which have a similar genetic variant, they are not true albinos.

According to the website of the Global White Lion Trust, less than ten white lions survive in their natural endemic habitat - the Greater Timbavati region of South Africa.