Patrick Wahome has helped organise protests in the central town of Nanyuki against the facility, and, like multiple eyewitnesses at the scene, told news agencies that the man died from a gunshot wound to the head.
The NGO Vocal Africa also posted on X about the killing.
Early on Tuesday, police began firing tear gas to disperse hundreds of protesters. Some waved Kenyan flags and one carried a white cross emblazoned with the phrase "Reject Ebola" in red.
More than 10 protesters were also detained by police, Reuters reporters said. At least two of them saw a body lying motionless with a large wound to the head in the back of a police van, though they said they had not witnessed the shooting themselves.
A police spokesperson said he had no information about the incident.
"Hooded police officers fired live bullets and arbitrarily arrested 19 protesters," the non-profit Kenya Human Rights Commission said in a statement posted on its social media accounts late on Tuesday.
Officers had also attacked protesters and journalists, the statement added.
The proposed 50-bed unit at Laikipia Air Base, near Nanyuki, has angered many Kenyans.
Protester Priscilla Imani told Reuters the area's association with the quarantine facility was also deterring tourists who come to climb Mount Kenya or see rhinos. "Laikipia is not a dumping site," she said.
US Ebola facility in Kenya fuels anger in a country with no cases
A country with no case
With no recorded cases of Ebola, many Kenyans are struggling to understand why their government is allowing the United States to build an Ebola facility in their country to treat US citizens.
Some protesters directed their anger at President William Ruto, who last week said his administration was doing "the right thing" by establishing the centre.
Others accuse the US of offloading the risk of caring for those exposed to the Ebola outbreak in eastern Democratic Republic of Congo and Uganda, where there have been more than 500 confirmed cases and 100 confirmed deaths.
Two people were killed during similar protests in Nanyuki last week. Police officers detain a protester taking part in a protest against a US-backed Ebola quarantine plan to establish a 50-bed facility at a Kenyan air force base intended to host Americans exposed to Ebola, in Nanyuki town, Laikipia County, Kenya,on 9 June, 2026.
A High Court judge has twice issued orders barring Kenya's government from taking steps to build or begin operations at the site.
Joshua Malidzo, a lawyer challenging the quarantine plan, said the court's deadline expired on Monday without the government complying.
US military planes have continued to ferry in staff and equipment after the court issued its orders, according to US and diplomatic sources and flight-tracking data, with several aircraft expected to land this week.
Satellite imagery seen by Reuters also shows a build-up of white tents since late May on a roughly 11-acre plot on the air base.
Requests for comment to a government spokesperson have gone unanswered.
A US-led facility for US citizens
The United States has said it is aware of the court challenge and is "working with the Kenyan government to resolve any objections".
Several US citizens have been exposed to Ebola in eastern Congo and Uganda. Six, including one who tested positive, were moved to a medical facility in Germany last month, while another was taken to the Czech Republic.
US President Donald Trump's administration has said it will not allow any Ebola cases to enter the US.
The Nanyuki facility is designated for Americans who have been exposed to the virus but remain asymptomatic. Kenyan officials have said the facility would also serve Kenyans and foreign nationals, but US officials have not confirmed this.
(with newswires)


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