A British safari parks entire troop of 13 Patas monkeys was killed in a fire that ripped through their shelter on Tuesday.

Woburn Safari Park in Bedfordshire, southern England, said staff were left "devastated" by the blaze, which broke out in the early hours of the morning.

The inferno was spotted by security guards. When firefighters arrived, they found the outbuilding housing the monkeys was "well alight and its roof had fallen in", Bedfordshire Fire and Rescue Service said.

"The building was 90 percent damaged by the fire.

"We have concluded that it is likely that the fire started accidentally in a generator."

The monkeys share the African Forest drive-through enclosure but no other animals are thought to have been affected. The monkeys were housed at night during the winter months.

According to website UK Zoos, only one other place in Britain -- Colchester Zoo -- has Patas monkeys, which are found in west and central Africa.

The fire comes less than two weeks after a blaze at London Zoo killed an aardvark, while four meerkats are also thought to have perished.

The fire broke out in the animal adventure section, destroying the cafe, shop and around half of the adjacent petting zoo.