The park's veterinary and management teams are closely monitoring the three surviving rhinos, which have been given fresh water.
As African wildlife numbers have plummeted because of poaching and habitat loss, conservationists and governments have increasingly turned to translocations in hopes of restoring populations in remote spots where they might be better shielded from the threats driving them to the brink elsewhere.
The loss is "shocking news", said Paula Kahumbu, the chief executive of WildlifeDirect, a conservation group in Kenya. In May, six black rhinos were moved from South Africa to Chad, restoring the species to the country in north-central Africa almost half a century after it was wiped out there. The Ministry of Tourism and Wildlife said salt poisoning may have caused the rhinos to perish as they struggled to adapt to saltier water in their new home.
Kenya transported 149 rhinos between 2005 and 2017 with eight deaths, the wildlife ministry said.
Fourteen black rhinos, eight from Nairobi National Park and six from Lake Nakuru National Park, were relocated to the Tsavo East National Park.
Between 1960 and 1995, black rhinos-distinguishable from white rhinos by their hooked upper lip and smaller stature-declined in number by a staggering 98 percent, according to the World Wildlife Fund.
Kenyans are now taking the government to task over the mishap.
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However, critics said May had caved in to pressure from Brexit supporters who want a complete break with Europe. "Not go into negotiation, sue them".
Eight of those died, not including the black rhinos at Tsavo East.
In a statement posted on her Facebook page, Wildlife Direct's Kahumbu noted the risks associated with translocation, writing, "Moving rhinos is complicated and risky, akin to moving gold bullion, [and] it requires extremely careful planning and security due to the value of these rare animals".
"Rhinos have died, we have to say it openly when it happens, not a week later or a month later", she said. The ministry had plans to translocate three more rhinos to the park but has since suspended them.
Another organisation, Save The Rhino, in a statement termed the death of the eight rhinos as tragic, saying this should inspire more conservation efforts.
The black rhino deaths were "unprecedented" in over a decade of relocation efforts by the Kenyan Wildlife Service to save the vanishing species, said officials.
LEAD IMAGE: Kenya Wildlife Service officials prepare to load a sedated black rhino into a transport crate on June 26, 2018.