The United States has said that another diplomat has fallen sick in Cuba with the symptoms of a mystery illness that has hit two dozen of his or her colleagues.
"This is the first medically confirmed case in Havana since August 2017. The number of Americans now affected is now 25," State Department spokeswoman Heather Nauert said yesterday.
At least one US official has also been hit by the same symptoms in China, as the mystery deepens over the cause of what Washington has previously suggested may have been some kind of attack.
Nauert said Washington had informed Havana of the latest incident on May 29, before it was formally medically confirmed, and reminded Cuba of its responsibility to protect diplomats on its soil.
Another US diplomat has reportedly been evacuated from Havana, but the results of his or her tests have not yet been released.
The apparent victims of the mystery ailment have suffered symptoms consistent with mild brain trauma -- including, in some cases, disorientation and hearing loss.
Some American officials in both China and Cuba reported hearing an unidentified noise before falling ill, and initial reports suggested they may have been hit by a secret sonic weapon.
But US intelligence and medical experts have been investigating for more than a year and seem no closer to identifying the cause.
After holding Cuba responsible for either carrying out the attacks or failing to protect its officials, the US recalled more than half of its staff and expelled 15 Cuban diplomats from Washington.
This marked a major diplomatic crisis following the countries' cautious revival of ties in 2015, but Cuba has firmly denied any role in or knowledge of the incident.
On June 10, the Cuban foreign ministry said: "We can confirm that we have no credible hypothesis or scientific explanation that justifies the retaliatory US measures.