The CIA evacuated an intelligence officer from Serbia who was suffering from symptoms associated with ‘Havana Syndrome’ as more cases of this mysterious neurological attack continue to affect American spies and diplomats, according to Daily Mail.

This incident in the Balkans – which hasn’t been previously reported – happened within recent weeks and continues a troubling uptick in attacks, according to a report by The Wall Street Journal.

About a week ago, a CIA agent fell ill with suspected Havana syndrome while on a work trip to India with CIA director William Burns and another agent experienced the same symptoms about a month ago in Vietnam.

All the unidentified officers reported same symptoms associated with the unexplained syndrome, which include headaches, pain, nausea or vertigo brought on by sounds, pressure or heat.

There have been 200 reported cases of the yet-unexplained illness, which has been colloquially named for its first reported case in 2016 at the US Embassy in Havana, Cuba. Roughly half of the cases involved CIA officers or their relatives, nearly 60 have been linked to Department of Defense workers or relatives, and about 50 involved State Department personnel.

Source: Azerbaijan State News Agency