The White House has said it is investigating “unexplained health incidents” after a report that two US officials in the Washington area experienced sudden symptoms similar to the “Havana syndrome” symptoms suffered by American diplomats and spies abroad.

The wave of mysterious brain injuries, beginning in Cuba in 2016, are deemed by the National Academy of Scientists to be most likely the result of some form of directed energy device, and the CIA, state department and Pentagon have all launched investigations.

CNN reported on Thursday that two possible incidents on US soil are part of the investigation. One took place in November last year near the Ellipse, the large oval lawn on the south side of the White House, in which an official from the national security council suddenly fell sick.

The other was in 2019 and involved a White House official walking her dog in a Arlington suburb of Washington. That incident was reported in GQ magazine last year.

That account said the incident happened after the staffer went past a parked van and a man got out and walked past her.