[3] It originated due to a deterioration in diplomatic relations between the governments of Morocco and Spain, after the latter admitted the transfer of the president of the Sahrawi Arab Democratic Republic, Brahim Ghali, to a Spanish hospital in La Rioja, in April 2021.

[4][5] A month after the hospitalization, the Moroccan security forces located on the border in Ceuta (and to a lesser extent those in Melilla) relaxed the last control mechanisms, allowing the passage of migrants from Morocco to the Spanish city,[6] most of whom made the journey by swimming.

[9][18] Karima Benyaich, Moroccan ambassador to Spain, stated in a statement about Ghali's hospitalization that "there are acts that have consequences and they have to be assumed",[19] and described the Spanish action as "inconsistent with the spirit of friendship and good neighborly relations between the two countries.

[22] In a statement on 20 May 2021, the Moroccan Foreign Minister, Nasser Bourita, confirmed that the discomfort in Rabat had its origin in the transfer of Ghali, protesting the fact that he had been received in Spain with a false passport and identity.

[26] On the morning of 18 May, the President of the Spanish Government, Pedro Sánchez, announced that those who had arrived irregularly would be "immediately returned" according to the bilateral agreement signed between Spain and Morocco.

[14] The Spanish Ministry of Defense also responded by moving 200 police officers to the area to support the 1,200 regular border patrol units, which would place armored vehicles along the beach to intercept new arrivals.

[27][26] Volunteers from the Spanish Red Cross also went to the scene to assist some immigrants suffering from hypothermia and severe fatigue after swimming across the breakwater area that marks the boundary between the two countries.

[25] Likewise, there was a greater flow of arrivals to the autonomous city of Melilla, also located in northern Morocco, where 80 immigrants crossed the double fence that separates the two nations.

[36] For the early hours of the day, after the effect of the Moroccan police reinforcement at the border and the pushbacks by the Spanish security forces,[37] the flow of arrivals had been significantly reduced; and, although these still occurred, they took place in small groups and spaced out over time.

[43] The Polisario Front questioned Istiqlal, reminding the Spanish government that the aforementioned party, in its relations, defends that "the territorial integrity of the Kingdom of Morocco will be incomplete without recovering all the occupied Moroccan lands, including Ceuta and Melilla".

[49] The leader of the Vox political party, Santiago Abascal, characterized the incident as a "Moroccan invasion" by "soldiers obeying their government," and called for action through the use of military force.

He also asked to guarantee the protection of minors arriving in the European country and denounced the "long history of abuse of the rights of asylum seekers and migrants" by Morocco.