June 28 (UPI) -- The State Department confirmed another U.S. diplomat in Cuba has experienced a mysterious health issue, bringing the total number of workers affected to 26.
On Thursday, a U.S. diplomat was "medically-confirmed" to have similar health effects similar to one case reported last week, State Department Spokeswoman Heather Nauert said in a statement.
Both recent cases were based on an incident in late May at a diplomatic residence where both individuals were present, Nauert said. The two cases are the first to be "medically-confirmed" since other cases of the illness were reported in August.
In March, the United States decided to permanently implement a scaled-down staff at its Cuban embassy after officials divulged 24 embassy employees there were victims of alleged sonic attacks.
The 24 individuals became ill with concussion-like symptoms of dizziness, fatigue and headaches after hearing loud, unusual notices. The two recent incidents bring the total number affected to 26.
"The health and well-being of our personnel remains our top priority here at the State Department," Nauert said.
The U.S. diplomats are being affected by what officials are calling "specific attacks" on U.S. workers in Cuba, The Hill reported.
The cause of the illness has yet to be determined, so "the inter-agency community continues to work diligently to determine the cause," Nauert said.
The Cuban government, which has an obligation under the Vienna Convention to protect diplomats, was informed of the attack on May 29 and assured the State Department it would investigate, she said.