Hidden cameras have captured the birth of three tiger cubs at London Zoo .

Three of the world's rarest tigers were born to five-year-old Sumatran tigress Melati on February 3 after a 106-day pregnancy.

The cubs arrived in the early hours, and all were born within an hour. The first cub was born at 12.28am, the second at 12.59am and the third made its entrance into the world at 1.18am.

The entire birth process was monitored using remote camera technology. The zoo has yet to establish the sex of the cubs.

Mother Melati and her cubs remain together inside special "cubbing dens" with Melati only occasionally venturing away from her babies for food.

Their birth will be a welcome addition to the zoo as it comes less than six months after the death of the zoo's first Sumatran tiger cub in 17 years. Keepers at the zoo were left ''very distraught'' after the cub was found drowned on the edge of the pool inside the tigers' enclosure, two weeks after its birth in October.

The cub had been the grandchild of the zoo's last tiger cub, Hari, the father of Melati.

Zookeeper Teague Stubbington said: "We couldn't be more delighted with our new arrivals, and with how Melati is responding to her three cubs.

"We've been observing them 24/7, and one of us is always on duty to keep an eye on the little ones throughout the night. We've even been able to observe key milestones like their eyes opening and their tentative first steps.

"While we still don't know whether they're boys or girls, we're starting to see their personalities develop. We've nicknamed one Trouble, as it's much bolder than the others - it was the first to start exploring its den, and we've spotted it waking up its siblings when they fall asleep."

In the 1970s, there were 1,000 Sumatran tigers in the wild but today there are believed to be 300 individuals. If numbers continue to decline at that rate, they face a very real threat of extinction within the next decade.

Therefore the cubs represent a great achievement for the zoo and the global breeding programme for the critically endangered species.

While mother Melati relaxes with her cubs, visitors to the zoo can still see six-year-old father Jae Jae in Tiger Territory, and there will be exclusive footage of the cubs on the zoo's YouTube channel throughout this month.