Spain will deploy its military to help restore order along its border with Morocco in the North African enclave of Ceuta after thousands of migrants surged into the Spanish territory, with at least 18 people dying during the crossing.

The move came after authorities in Ceuta appealed to Spain's central government for additional support as the border situation spiraled out of control Thursday, when large crowds breached the frontier fence.

The Spanish government said the Armed Forces would assist the Civil Guard in maintaining security across Ceuta. It also announced that Prime Minister Pedro Sanchez and Interior Minister Fernando Grande-Marlaska would travel to the enclave Friday to assess the situation.

"The situation is absolute chaos," Rachid Sbihi, head of the association representing Civil Guard officers stationed along Ceuta's border, told The Associated Press (AP). "It's not possible to give precise numbers, but there are thousands of migrants crossing," he said, adding that the border had "totally collapsed."

Achraf Maimouni, a member of the Moroccan Association for Human Rights in northern Morocco, described the situation as "exceptional."

"The Tarajal border was opened under unusual circumstances this morning, and people crossed," he said.

Video footage showed crowds of people, mainly Moroccans, walking around the breakwaters at Tarajal Beach and onto local roads. While most appeared to be young men, there were also families with women and small children.

"Viva Espana!" some shouted to a freelance photographer working for the AP. It was not immediately clear what prompted so many migrants to cross into Ceuta.

Spain's government delegation in Ceuta said at least 18 people died Thursday during the chaos. It did not provide details on the circumstances of the deaths, but bodies could be seen floating in the water. Dozens have died this year trying to reach Ceuta, according to local authorities.

The escalation along the frontier between Spain and Morocco comes after a surge in migrants attempting to reach the enclave, mainly by swimming, on Wednesday.

Moroccan authorities have not publicly commented on the crossings, and Morocco's Interior Ministry did not respond to requests for comment.

Spain's Interior Ministry said the Moroccan government was "closely cooperating" with Spain to handle the situation and that Moroccan police were stopping "numerous people" trying to cross the border. Both countries agreed to work together "for the return, as soon as possible, of all the people who entered Ceuta illegally."

The ministry earlier said it would guarantee the safety of citizens and the integrity of the nation's border but that the Spanish government could not declare a national emergency, as local authorities had requested, over migration concerns.

The chaos had ripple effects in Italy, another key destination for migrants. Premier Giorgia Meloni threatened to suspend Italy's participation in the Schengen Agreement with Spain "to defend our borders and ensure the safety of our citizens," though Italy does not share a border with Spain.

Ceuta authorities had previously linked the surge to a Spanish Supreme Court ruling earlier this month that barred authorities from immediately returning migrants who arrive by sea without due process. The ruling does not apply to migrants who enter Spain by land, including by climbing over the border fence.

But some activists in Morocco expressed doubt that the ruling was behind the surge, arguing that most migrants would have been unaware of the legal decision.

Spain is a main entry point into Europe for migrants seeking better economic opportunities or an escape from violence in their home countries.

To reach Ceuta, located on the northern coast of Africa, migrants often swim from the Moroccan town of Fnideq, covering about 3.1 miles (5 kilometers) to reach Spanish territory. Others attempt the crossing from the nearby town of Belyounech, where the distance is shorter.

The scenes of people streaming across the frontier recalled the border crisis of May 2021, when more than 8,000 migrants poured into Ceuta in just two days.

At the time, Morocco was accused of easing border controls and allowing migrants to cross into Ceuta after Spain allowed Polisario Front leader Brahim Ghali to receive treatment at a Spanish hospital, triggering a diplomatic crisis between Rabat and Madrid. The pro-independence Polisario Front has for decades claimed to be the legitimate representative of the Sahrawi people of Western Sahara. Morocco claims Western Sahara as its own.

Juan Jesús Vivas, the head of Ceuta's regional government, called on the national government to declare an emergency on national security grounds, asking for more police officers and for the military to be deployed to the border "to guarantee the inviolability of the frontier and citizen safety."

He warned Wednesday that migrant reception centers were overwhelmed, with hundreds of people sleeping on the streets after more than 1,500 migrants entered the territory over the past week. Thousands more crossed overnight and on Thursday.

Spain's Interior Ministry, which tracks irregular migration, would not confirm the number of migrants who had reached Ceuta in recent days but said it would publish its next migration report Aug. 3. As of July 15, nearly 3,000 migrants had entered Ceuta by land or sea this year, according to ministry figures.

Legislation governing declarations of national emergencies does not classify migration flows as a national security risk, according to the ministry, which said government agencies were "coordinating to respond with speed and effectiveness to the situation in Ceuta."

Ceuta, perched on a historic isthmus, has been a Spanish possession since 1580. Its mixed population of Christians and Muslims, Spaniards and Moroccans, along with cross-border workers, has long lived in relative harmony behind a border fence that many desperate migrants from across Africa attempt to cross in search of a better life in Europe.