Argentine jet fuel providers in Buenos Aires refused to service Cuban state airline Cubana this week citing concerns over U.S. trade sanctions on Cuba, the Havana-based carrier said late on Wednesday, prompting multiple unexpected flight cancellations.

Cubana de Aviacion S.A., which operates flights within Cuba and to various cities internationally, said it had cancelled flights on April 23 and 24, as well as other flights contracted to partner airlines, forcing the company to rebook passengers or provide refunds.

“This decision is due to the refusal of aviation fuel supply companies in the Republic of Argentina to provide service to the airline, invoking the provisions of the United States blockade measures against Cuba,” the airline said in a brief statement.

Argentina’s foreign ministry and Office of the Presidency did not immediately respond to a request for comment on the matter.

The U.S. trade embargo against Cuba was put in place following Fidel Castro’s 1959 revolution.

-Reuters