The tiny cubs come hot on the heels of their older sister Lily, who was born this summer and hand-reared after she was rejected by her mother.

The cubs are now a month old but their gender remains a mystery as the keepers are leaving them in strict seclusion so that they can bond with their mother Fidda. They have yet to meet their father Qays.

Barbary lions are extinct in the wild and Lily was the first of the north African sub-species to be born in Ireland.

It's a nerve-wracking time for the keepers at the Zoo as they wait to see if the Barbary lions will manage to form a successful family unit this time.

The fear is that they could be rejected by either parent, meaning they will have to be hand-reared - if they haven't been killed.

A zoo spokesperson said: "It's still trial and error, and the keepers have had no human contact with the cubs. They are not on show as the mother needs to spend time with the cubs for the first three-four months to build a bond.

"We want to have a mother-and-baby bond, as opposed to two more hand-reared lions. They are not out in the paddock with their father and aunt yet and we have no idea how they will react to them."

Lions reared in a pride have a better chance of going on to breed successfully than do hand-reared animals such as Lily.

After Lily was rejected by her mother, she was reared by a keeper at home before returning to the zoo.

"She's very big. She bites a lot now - nobody can go in with her any more," the spokesperson said.

" She's more lion-like now and she roars much more."