In a Facebook post late on Tuesday night, Minister of State for Human Rights El Mustapha Ramid warned Madrid not to mess with Rabat. “What did Spain expect from Morocco, which sees its neighbor hosting the head of a group that took up arms against the kingdom?” he wrote.

Ramid was referring to Brahim Ghali, who heads up Polisario, a Western Sahara independence group, in conflict with Morocco. In April, Ghali was taken to Spain to be treated for Covid-19.

“Morocco has the right to lean back and stretch its legs … so that Spain knows that underestimating Morocco is costly,” Ramid added.

Spain’s Foreign Minister Arancha Gonzalez Laya said on April 23 that Ghali, 71, had arrived in Spain from Algeria “strictly for humanitarian reasons, for medical treatment.”

On Wednesday, citing a document seen by the agency, Reuters reported that Ghali had been summoned by Spain’s high court to appear on June 1 on charges of war crimes.

Spanish officials accused Moroccan authorities on Tuesday of being passive to a wave of migrants running and swimming towards the Spanish border. Some said Moroccan border guards actually ushered migrants through the gate. Around 8,000 entered Spain’s North African enclave of Ceuta at the beginning of the week, but Spain has since deployed troops to return many to Morocco.