LISBON, Portugal (AP) — Spain’s foreign minister summoned Cuba’s top diplomat in Madrid on Sunday to explain why Havana has revoked the press credentials of five journalists on the island working for Spanish state news agency Efe.

The Spanish embassy in Havana is also working with Cuban authorities in an effort to ensure the return of the Efe team’s credentials, which they need in order to work in Cuba, Spanish diplomatic sources told The Associated Press.

Efe said Cuban officials offered no explanation about why — or until when — they were revoking the credentials of three reporters, a photographer and a cameraman.

The step late Saturday came two days before a planned opposition protest march scheduled for Monday in Cuba. The Cuban government has outlawed the demonstration but organizers have urged people to take to the streets anyway.

Spanish Foreign Minister José Manuel Albares summoned Cuba’s charge d’affaires for a meeting, a Spanish diplomatic source said. Cuba currently has no ambassador in Madrid.

The source, who spoke on condition of anonymity in accordance with foreign ministry rules, did not elaborate on what was said at the meeting.

The Federation of Spanish Journalists’ Associations said Cuba’s measure was “a clear violation of international norms on freedom of the press” and urged the Cuban government to reconsider.