US officials are investigating possible cases of Havana syndrome illness in Colombia, days before a visit by the Secretary of State, US media say.
US embassy staff in Bogota may have been injured by the mysterious illness, which causes a painful sound in the ears, fatigue and dizziness.
First reported in Cuba in 2016, US diplomats around the world have since reported cases of the syndrome.
Its origins are unknown, with some speculating it is a type of weapon.
On Tuesday, the Wall Street Journal first reported that emails sent by US Ambassador to Colombia Philip Goldberg confirmed a number of "unexplained health incidents" or UHIs - the term used for Havana syndrome by the US government - since mid-September.
Colombian President Iván Duque told the New York Times that the country is investigating the reports. He added that the US is leading the inquiry.