An entire herd of elephants from a British zoo will be released into the wild in Kenya in what conservationists have hailed as a world first.

The 13 elephants live at Howletts Wild Animal Park in Kent, southern England, and will be flown more than 7 000km to Kenya. Twelve of the elephants were born and raised in Kent and one was born in Israel. None of the animals has ever lived in the wild, reports CNN Travel.

The group weighs 22 680kg in total and includes three calves. It will be the first time that a herd of elephants has been rewilded in the world, organisers say.

The elephants will be transported in individual cages customised to their needs, and vets will be on hand throughout the flight, according to the Aspinall Foundation website. Conservationists are raising funds for the project.

The Aspinall Foundation, an animal conservation charity, said it hoped the project would discourage the global trade in elephants and encourage the return of animals to the wild where possible, adding that no elephants belonged in captivity.

"This is an incredibly exciting project and a genuine world-first," says Damian Aspinall, chairman of the Aspinall Foundation. "As with any conservation project of this magnitude, there are obviously big risks, but we consider them well worth it to get these magnificent elephants back into the wild where they belong."

The charity is working on the project with the Sheldrick Wildlife Trust and the Kenya Wildlife Service, and two sites in the south of Kenya are under consideration for the elephants’ release.

"Since the 1970s, we have been helping elephants, providing a wild future to more than 260 rescued orphans and operating extensive protection projects to ensure they, their wild born babies and their wild kin are best protected throughout their lives," says Angela Sheldrick, CEO of the Sheldrick Wildlife Trust.