Staff at Leipzig zoo shot dead one of two escaped lions after a tranquiliser dart failed to sedate it, the zoo has admitted.

The young male lions, named Majo and Motshegetsi, escaped their enclosure by leaping over a moat and entered the main grounds of the zoo on Thursday morning before the park opened to the public.

After the zookeepers implemented an emergency lockdown, Majo was successfully corralled back into the enclosure, but Motshegetsi remained agitated and had to be shot, the zoo said.

“This is a very, very sad ending, which I really would not have wished for,” the zoo's director Joerg Junhold told reporters. “But we had no choice.”

“In this case personal safety had to take priority.”

Majo and Motshegetsi were both 15-months-old and had only been at the zoo for a month after being transferred from a zoo in the Swiss city of Basel.

After their escape, the lions were discovered in a terrified state in undergrowth a short distance from their enclosure.

About 40 zookeepers then surrounded them with vehicles in an attempt to drive them back.

According to local media, Majo was returned to the enclosure after three hours, with staff reportedly using a fence to coral the animal, but Motshegetsi broke through the barrier and the keepers were forced to take action.

“After Majo was caught and Motshegetsi was hit with a tranquiliser dart, we were hopeful that the breakout could end without any loss of life,” Mr Junhold said.

But staff then decided they had lost control of the situation and shot the lion.

“Human safety always comes first,” Mr Junhold said.

The enclosure had been in use at the zoo for 15 years and there had never previously been problems, Mr Junhold added.

Leipzig zoo has successfully bred over 2,000 lions in the past, and 250 rare Siberian tigers.

In March one tiger at the zoo killed another after a partition separating them was removed.

Where not to visit if you love animals Show all 9 1 /9 Where not to visit if you love animals Where not to visit if you love animals Monkey shows Chimpanzees are forced to perform demeaning tricks on leashes and are often subject to cruel training techniques. Animals who are confined to small, barren enclosures and forced to perform unsurprisingly show symptoms of stress and depression. Chimpanzees have been documented rocking back and forth, sucking their lips, salivating and swaying against enclosure perimeters in distress. Getty Where not to visit if you love animals Marine parks Some parks confine orcas to concrete tanks and force them to perform meaningless tricks for food - many die in captivity. Orcas are highly intelligent and social mammals who may suffer immensely, both physically and mentally, when they're held in captivity. Getty Where not to visit if you love animals Tiger shows Tigers are forced to live in an unnatural and barren environment and have to endure interactions with a constant stream of tourists. Since tigers never lose their wild instincts, across the world they are reportedly drugged, mutilated and restrained in order to make them “safe” for the public. However, every year, incidents of tiger maulings are reported at this type of tourist attraction. Getty Where not to visit if you love animals Donkey rides Sunning on the beach is great for humans – we can take a quick dip or catch a bite to eat when we get too hot or hungry. But it's pure hell for donkeys who are confined to the beach and forced to cart children around on the hot sand. Some donkey-ride operators at beach resorts in the UK even keep the animals chained together at all times. Getty Where not to visit if you love animals Swimming with dolphins Some marine parks use bottlenose dolphins in performances and offer visitors the opportunity to swim with dolphins. Unfortunately, people are often unaware that these animals are captured in the wild and torn from their families or traded between different parks around the world. Getty Where not to visit if you love animals Canned hunting Lions are confined to fenced areas so that they can easily be cornered, with no chance of escape. Most of them will have been bred in captivity and then taken from their mothers to be hand-reared by the cub-petting industry. When they get too big, they may be drugged before they are released into a "hunting" enclosure. Because these animals are usually kept in fenced enclosures (ranging in size from just a few square yards to thousands of acres), they never stand a chance of surviving. Getty Where not to visit if you love animals Running of the Bulls Every year, tourists travel to Pamplona for the Running of the Bulls. The bulls who are forced to slip and slide down the town's narrow cobblestone streets are chased straight into the bullring. They are then taunted, stabbed repeatedly and finally killed by the matador in front of a jeering crowd. The majority of Spaniards reject bullfighting, but tourists are keeping the cruel industry on its last legs. Getty Where not to visit if you love animals Horse-drawn carriages City streets are no place for horses. The animals toil in all weather extremes, suffering from respiratory distress from breathing in exhaust fumes as well as numerous hoof, leg and back problems from walking on pavement all day long. As easily spooked prey animals, horses subjected to the loud noises and unexpected sounds of city streets are likely to be involved in accidents, even deadly ones. Getty Where not to visit if you love animals Zoos The zoo community regards the animals it keeps as commodities, and animals are regularly bought, sold, borrowed and traded without any regard for established relationships. Zoos breed animals because the presence of babies draws visitors and boosts revenue, yet often, there's nowhere to put the offspring as they grow, and they are killed, as we saw with Marius the giraffe in Denmark. Some zoos have introduced evening events with loud music and alcohol which disrupt the incarcerated animals even further. EPA

The zoo is now planning a security review.

The last time the Leipzig saw a big cat breakout was in October 1913, when six lions reportedly escaped a private menagerie in the east German city during a festival. The escapees sparked a city-wide hunt, ending with the killing of all six of the lions, which were then exhibited at Leipzig zoo, the Leipziger Volkszeitung reported.