The unexplained attacks against U.S. diplomats that have baffled experts since they were first reported in Cuba in 2016 have now afflicted more than 130 American personnel stationed overseas, The New York Times reports. Dozens more cases have reportedly come to light as the Biden administration has stepped up efforts to investigate the alarming trend, which was initially thought to be concentrated in China and Cuba but has now been documented throughout Europe and Asia. The mysterious ailments, which some experts believe are caused by microwave or directed-energy weapons, have left some U.S. personnel with permanent brain injuries and chronic health issues. Walter Reed doctors have reportedly warned that some victims are vulnerable to suicide.

Current and former officials interviewed by the Times spoke of one previously unreported incident in 2019 when a military officer stationed overseas was suddenly struck by nausea and headaches after pulling into an intersection. His 2-year-old son, who was seated in the back of the vehicle, is said to have also reacted to the sudden “attack” and started crying as they pulled into the intersection. The mysterious ailment disappeared for both of them as soon as the car moved out of the intersection. Although Pentagon officials have expressed suspicions about Russia being behind the attacks, the Biden administration has yet to draw any conclusions. Three CIA officers have reportedly been left with serious health issues after overseas attacks since December, and the agency has set up a special unit to investigate the matter.