NAIROBI - Seven black rhinos have died at the Tsavo East National Park following translocation by wildlife conservationists late last month, wildlife official said on Friday.

A Kenya Wildlife Service (KWS) official who did not want to be named said the seven rhinos which were being moved from Nairobi National Park to Tsavo East National Park died in unclear circumstances but noted that efforts are underway to establish the cause.

A senior official at the World Wide Fund (WWF) which partnered with the KWS to translate the rhinos expressed concern about the loss.

"We are extremely concerned to hear reports that seven black rhinos have died in Tsavo East National Park after being moved from Nairobi and Nakuru National Parks as part of a translocation program by Kenya Wildlife Service (KWS)," WWF-Kenya CEO Mohamed Awer said in a statement issued in Nairobi.

A total of 14 rhinos were translocated from the Nairobi and Nakuru National Parks to Tsavo East National Park in a new rhino sanctuary in an exercise which was launched on June 26.

The sanctuary in the expansive park is a joint effort between KWS and WWF. KWS is yet to comment on the death of the rhinos.

"Translocating wild animals of this size is extremely challenging and not without risk, but black rhinos are under enormous threat so efforts to try and better protect them, such as translocations, are crucial for future generations," Awer said.

"WWF is in contact with KWS to confirm the full situation and offer our support in launching an urgent independent assessment of what happened," said Awer.

According to KWS, Kenya had at the end of 2017, a rhino population of 1,258 having grown from less than 400 rhinos in 1980s.

Unrestrained poaching in the 70's and 80's occasioned a substantial deterioration in the rhino population, from upwards of 20,000 to approximately 300 individuals in 1989.

The surviving rhinos are being corralled into fortified sanctuaries with the aim of enhancing breeding.