The move is part of a project that will see the East African nation receive a total of 36 white rhinos, which have been absent in the country for decades.

Remains of the endangered species have been found in the Ngorongoro Conservation Area in northern Tanzania, said Emmanuel Kaaya, rhino specialist with the local authority.

But "they vanished due to poaching in the 1970s," he added.

Tanzania's overall population of related black rhinos has fallen from an estimated 10,000 in the 1970s to just 212 in 2021, according to the latest report by the International Rhino Foundation (IRF).

South Africa accounts for the majority of the world's remaining white rhinos, with an estimated 13,991 in 2023, the report said.

The origins of the name are uncertain since both species are grey, though "white" rhinos tend to be larger, with a different mouth and longer front horn.

A poaching crisis in South Africa has led to the loss of more than 10,000 rhinos since 2007, the IRF said.

"Rampant poaching has put them at great risk. That is why we have started relocating them to countries like Botswana, Rwanda, the Democratic Republic of Congo, and now Tanzania," Inkosi Gumede Zwelinzima, a South African community leader, said at the handover ceremony, according to a statement from the Ngorongoro Conservation Area Authority.

"Despite these challenges, we have successfully increased the white rhino population through careful conservation," he added.

Local authorities said the new arrivals will initially be kept in an enclosure while they adapt to the local climate and food, before being released into the conservation area's famed Ngorongoro crater.

The Tanzania Wildlife Research Institute says conditions are ripe for the rhinos to "thrive", and that they could eventually be introduced to other reserves such as Mikumi and Burigi-Chato.