‘Havana syndrome’ unlikely caused by hostile foreign power, CIA says

The US embassy in Havana. Since the original outbreak of the symptoms, more than 1,000 cases have been studied around the world. Photograph: Desmond Boylan/AP

An initial CIA investigation into the mysterious set of symptoms known as Havana syndrome has found that it is unlikely to be the result of a worldwide campaign of attacks by a foreign power against US diplomats and spies.

However, two dozen cases, including some of those originally afflicted in Havana in 2016, could not be explained and would be further studied for evidence of a possible attack, according to a senior CIA official who briefed the US press.