Twin tiger cubs Rasmi and Mandala have been seen exploring their enclosure at the Frankfurt Zoo, after making their public debut this week.

This was the first time the Sumatran tiger babies could be viewed by the public since they were born.

According to director of the Frankfurt Zoo, Christina Geiger the tiger family is doing very well, the parents are attentive and the cubs lively and curious - that is when they aren't sleeping.

The Sumatran tiger is a critically endangered species and great efforts are needed to preserve these animals in their natural habitat, Geiger said.

Rainforests in Sumatra, where the animals are from are threatened by deforestation, roads and the building of plantations - "What's more, the prey animals of these animals are poached and hunted, meaning that they are in competition with humans for food, which of course increases the pressure, meaning that not only are the tigers themselves poached, but they are also deprived of their food source", she added.

The cubs are expected to stay with their parents for about a year and zoo-goers will be able to observe them as they keep climbing and playing in the enclosure, as well as occasionally hiss at a curious visitor.