The Spanish Supreme Court ruled Monday that a 2021 mass deportation of minors from the Spanish enclave of Ceuta to Morocco was illegal.

Hundreds of unaccompanied minors were part of a group of around 12,000 people who tried to enter Ceuta from Morocco in May 2021 by scaling a border fence or swimming around it.

The mass border crossing took place amid a diplomatic dispute between Madrid and Rabat regarding Western Sahara.

After the border crossing, approximately 700 minors were deported to Morocco, despite Spanish law that requires the government to take administrative steps for each minor it deports, including collecting information on their circumstances and holding a hearing if deemed necessary.

Government lawyers cited a 2007 agreement between Spain and Morocco outlining the process for assisted returns to Morocco in the case of "exceptional circumstances," but the Supreme Court dismissed this defense, ruling that it did not supersede Spanish law.

The court ruled that the deportation violated the "physical and moral integrity" of the migrants and breached the European Human Rights Convention. It cited Article 4 of Protocol No. 4 of the European Human Rights Convention, which says that the "Collective expulsion of aliens is prohibited."

The Spanish Interior Ministry had defended the 2021 deportation of youths and has denied that it breached international law.

Many of those who crossed the border in 2021 were believed to be Sub-Saharan migrants who sought to find a better life in Europe.

Tens of thousands of migrants from Sub-Saharan Africa make the trip from Northwest Africa to Spain each year.

More than 6,600 migrants died while trying to reach Spain by boat last year from West Africa, according to the Spanish group, Caminando Fronteras, which works to defend the rights of migrants.

Some material for this report came from Reuters and The Associated Press.