GPS dis­rup­tions have been af­fect­ing flights in and around Pi­ar­co In­ter­na­tion­al Air­port, ac­cord­ing to re­port­ing by The New York Times over the week­end.

Pi­lots from Caribbean Air­lines and Co­pa Air­lines have told air traf­fic con­trollers that their nav­i­ga­tion sys­tems were be­ing jammed, prompt­ing guid­ance from radar to en­sure safe land­ings.

“A pi­lot of a dif­fer­ent com­mer­cial flight that day, op­er­at­ed by Caribbean Air­lines, blunt­ly told an air traf­fic con­troller that his nav­i­ga­tion sys­tems were be­ing jammed, be­fore ask­ing to be guid­ed in­to Trinidad,” the re­port says.

The in­ter­fer­ence is linked to an es­ca­lat­ing stand­off be­tween the Unit­ed States and Venezuela, with both coun­tries’ mil­i­taries re­port­ed­ly jam­ming satel­lite nav­i­ga­tion sig­nals in the Caribbean. U.S. war­ships, in­clud­ing the air­craft car­ri­er U.S.S. Ger­ald R. Ford, have been con­duct­ing op­er­a­tions tar­get­ing Venezue­lan-linked drug traf­fick­ing, while Venezue­lan forces have jammed GPS cov­er­age near mil­i­tary bases, oil re­finer­ies, and pow­er plants, ac­cord­ing to da­ta from Stan­ford Uni­ver­si­ty and Spire Glob­al.

“These dis­rup­tions are de­fen­sive in na­ture,” Lo­gan Scott, a ra­dio fre­quen­cy ex­pert, told The New York Times. “But the spillover ef­fect is felt in civil­ian air and sea traf­fic.”

Stan­ford da­ta show that one in five flights in the Caribbean has ex­pe­ri­enced GPS is­sues since ear­ly Sep­tem­ber, ac­cord­ing to the re­port.

The Fed­er­al Avi­a­tion Ad­min­is­tra­tion has is­sued warn­ings to flights near Venezuela and Puer­to Ri­co, cit­ing “an in­crease in state air­craft op­er­a­tions.” Pi­lots in the Caribbean have re­port­ed in­ter­mit­tent GPS loss, some­times forc­ing nav­i­ga­tion by radar or vi­su­al land­marks.

Co­pa Air­lines said it is “tak­ing all nec­es­sary pre­cau­tions and is in close and fre­quent con­tact with all rel­e­vant avi­a­tion au­thor­i­ties,” while Caribbean Air­lines con­firmed pi­lots had ex­pe­ri­enced jam­ming but of­fered no fur­ther de­tails.

The in­ter­fer­ence comes amid in­creased U.S. mil­i­tary ac­tiv­i­ty in the Caribbean, in­clud­ing the seizure of a Venezue­lan oil tanker be­tween Grena­da and Trinidad, and added naval es­corts by the Venezue­lan Navy.