CEUTA, Spain (AP) — About 60,000 migrants have crossed from Morocco into Spain's tiny Ceuta territory in the past 24 hours, Ceuta's president said Friday, a figure that is equivalent to 70% of the population of the self-governing city in North Africa.

But roughly half of them have already made their way back voluntarily, the Spanish government said, after the sudden arrival of so many migrants triggered chaos and a humanitarian crisis.

Spain deployed its armed forces and additional police to restore order in Ceuta while security forces clashed with migrants on the Moroccan side of the border. At least 41 migrants died, including some who drowned or were killed in a stampede to cross a breakwater barrier near a border checkpoint.

"The situation that Ceuta is going through is absolutely unsustainable," Ceuta President Juan Jesús Vivas told journalists.

Meanwhile, migrants from Morocco also attempted to cross into Melilla, Spain's other territory at the tip of North Africa, where they clashed with police.

Spanish Prime Minister Pedro Sánchez visited Ceuta on Friday and condemned the border breach, which he described as "a violation of Spain's territorial integrity."

Sánchez blamed human smugglers for the crisis, saying they "deceive so many young people and ultimately lead many of them to their deaths," whether in the ocean or in the autonomous city.

Spain's interior ministry, which initially refused to share estimates from the border, released its own figures shortly after Vivas' spoke, estimating that some 50,000 people had crossed from Morocco since Thursday. It added that 25,000 had already returned to Morocco, with hundreds more going back by the hour.

Video footage early on Friday showed hundreds of migrants gathered on a hill overlooking Ceuta being dispersed with tear gas by Moroccan forces, while others continued to swim to the Spanish territory. But by Friday afternoon, most migrants were trying to leave Ceuta given the dire conditions there.

Rachid Sbihi, who leads a local workers association representing Civil Guard officers, described the situation as a "serious humanitarian crisis," saying thousands of migrants, including unaccompanied children, were left sleeping in parks and on sidewalks, while others roamed the streets aimlessly.

"It's chaotic," Sbihi said.

European Commission President Ursula von der Leyen said the "images coming from Ceuta are unacceptable."

"We cannot allow anyone to come to our Union without abiding by our rules," she said Friday in an online statement. "Dangerous crossings must stop immediately. Smuggling networks must be dismantled. And returns must be swift, as our rules allow."

Dozens died in the chaos

Some of the 41 people who died had drowned, Sbihi said, but some were also killed in a stampede to cross the breakwater fence at Tarajal Beach, an urban beach near a border checkpoint with Morocco. The waters near the border fence were littered with buoys, shoes and other abandoned belongings.

Many young Moroccans who crossed into Ceuta told The Associated Press that they had hoped to find better work opportunities in Spain but were returning given the mayhem in Ceuta.

"There's nothing at home. I'd have to work 12-hour shifts for a meager wage. That's why I came here," said 21-year-old Abdulah Buji, who hails from the city of Tetouan. "But I haven't found any opportunities here either, so I have to go back."

Moroccan police used water cannons and fired warning shots into the air to prevent migrants from crossing into Ceuta, according to rights groups in Morocco.

"Despite the heavy police presence, people crossed through the waterway, while the land border remained closed," said Achraf Maimouni, a human-rights activist in Fnideq, the Moroccan city bordering Ceuta.

Morocco's ambassador to Spain expressed hope that those who crossed from Morocco into the Spanish territory would return. Karima Benyaich described the situation in Ceuta as difficult, saying it had unfolded against Morocco's wishes.

"We have always prioritized legal, orderly and safe migration for all," she said. Benyaich did not comment on what prompted the migrants to cross into Ceuta.

To reach Ceuta, on the northern African coast, migrants often swim from the Moroccan town of Fnideq, covering about 3 miles (5 kilometers) to reach Spanish territory. Others attempt the crossing from the nearby town of Belyounech, where the distance is shorter.

Border surge linked to Supreme Court ruling

The authorities in Ceuta and Madrid have linked the border surge to a recent decision by the Spanish Supreme Court that ruled migrants arriving by sea could not be summarily deported, unlike those who cross by land or climb the border fence.

Sánchez said migrant smugglers misinterpreted the ruling.

"It appears that this interpretation of the Supreme Court's ruling spread like wildfire over the past few hours through the networks of human trafficking organizations, triggering the kind of mass surge we witnessed yesterday," Sánchez said.

Some activists in Morocco expressed doubt that the ruling was behind the surge, arguing that most migrants would have been unaware of such legal decisions.

Spanish prime minister has bucked anti-immigration trend

Sánchez has bucked the anti-migration trend that has gained ground across Europe and in the U.S.

Earlier this year, his government moved to give residency and work permits to hundreds of thousands of migrants already living in the country without permission.

Sánchez, a Socialist, argued that it would be good for the economy and the demographics of an aging Spain. Migrants who entered irregularly after Jan. 1 this year were not included.

But his critics have jumped at the opportunity to attack his policy, saying it encouraged more migrants to come.

"Sánchez allows Spain to be invaded through Ceuta," Spanish conservative politician Isabel Díaz Ayuso wrote on X.

Sánchez on Friday defended his migration policy and distanced it from the events unfolding in Ceuta.

The chaos had ripple effects abroad. Italian Premier Giorgia Meloni threatened to suspend her country's open-border Schengen agreement with Spain "to defend our borders and ensure the safety of our citizens," even though Italy does not share a border with Spain and is also an entry point for tens of thousands of migrants crossing the Mediterranean each year.

French Interior Minister Laurent Nunez said France would also strengthen border checks with Spain.

"This crisis in Ceuta has nothing to do with the regularization of migrants adopted by the Government of Spain, as is being falsely claimed by some," the Spanish government said in a statement late Thursday after Meloni's announcement.

Pressure grows on second Spanish territory in Africa

Migrants from Morocco also attempted to cross into Melilla, the other Spanish territory at the tip of North Africa.

There was widespread chaos in Bni Nsar, the Moroccan town bordering the Spanish territory, where migrants clashed with police, throwing rocks and setting police vehicles ablaze, according to local media and rights groups. They reported injuries among security forces and the arrest of dozens of people attempting to cross.

Like Ceuta, Melilla is an autonomous Spanish city on the North African coast. Many Moroccans consider both cities to be occupied territory.

Ceuta has been a Spanish possession since 1580. Its mixed population of Christians and Muslims, Spanish and Moroccan residents and day workers, lives in relative harmony.