Spanish Prime Minister Pedro Sanchez is defending the way Moroccan and Spanish police repelled migrants last week as they tried to cross the shared border into the North African enclave of Melilla, depicting the attempt in which at least 23 people died as "an attack on Spain's borders."

"We must remember that many of these migrants attacked Spain’s borders with axes and hooks," Sanchez said during an interview Monday with The Associated Press (AP). "We are talking about an attempt to assault the fence that was evidently carried out in an aggressive way, and therefore what Spain’s state security forces and Moroccan guards did was defend Spain’s borders."

Authorities in Morocco have blamed the deaths on a "stampede" of people that formed early Friday as hundreds attempted to scale or break through the 12-meter (29-foot) iron double fence.

The barrier surrounds Melilla, a town of 85,000 separated from the Spanish mainland by the Strait of Gibraltar.

Nonprofits working in northern Africa and human rights organizations have deplored the treatment the migrants received from police on both sides. But they have also directed their blame at Spanish and European Union officials who they say have essentially outsourced border controls to Morocco and other states.

Sanchez, whose left-to-center government is trying to improve ties with Morocco following an acrimonious diplomatic dispute over Western Sahara, has refused to criticize the crackdown.

Speaking at the palace on the outskirts of Madrid that hosts his office and residence, Sanchez told AP that his thoughts were with the families of those who died. But he blamed the tragedy on "international human trafficking rings who are profiting from the suffering of human beings who only want to seek a better life."

"I insist, these are international mafia groups that are not only damaging the territorial integrity of Spain but also that of Morocco, which is a country suffering that irregular migration."

Sanchez spoke to AP on the eve of hosting NATO leaders in a summit that aims to redraw the defense alliance’s strategy for the next decade. While Russia’s invasion of Ukraine will take center stage at the Wednesday and Thursday meeting, the group will also debate its posture on Africa, where Russian mercenaries are adding to concerns about migration, extremism and the impacts of poverty and climate change.

Footage uploaded to social media shows how a large number of migrants approached a section of the fence and began scaling it. Some of the migrants hurled rocks at Moroccan anti-riot police trying to stop them. At one point, the fence collapses, sending many of the migrants to the ground from a height of several meters.

In at least one video released by Spanish online news website eldiario.es, Spanish guards can also be seen escorting migrants back to the Moroccan side, a practice that human rights activists say denies the right of refugees to apply for asylum on European soil.

More gruesome videos and photos posted online appear to show the aftermath of the crossing attempt, with scores of young men, some of them motionless and others barely moving and bleeding as Moroccan security forces stood over them.

At least 76 civilians and 140 security officers on the Moroccan side, and 60 National Police and Civil Guard officers on the Spanish side, were injured, according to their respective governments. A small group of African men who did make it across the fence was taken to a migrant holding center in Melilla.

Moussa Faki Mahamat, head of the continent’s largest grouping of countries, the African Union, has called for an investigation into the deaths. In a tweet, Mahamat said he wanted to "express my deep shock and concern at the violent and degrading treatment of African migrants," adding that all countries have "obligations under international law to treat all migrants with dignity and to prioritize their safety and human rights while refraining from the use of excessive force."

While Moroccan authorities say 23 people died in addition to scores of injuries both among the migrants and border guards, activists claim that the death toll is higher and denounce the EU's policy of striking deals with Morocco and other states like Turkey to control migration flows.

A group of 51 human rights groups said Monday in a joint statement distributed by Spanish NGO Walking Borders that the deaths "are the tragic example of the European Union's policies of externalizing its borders, with the complicity of a southern country, Morocco."

"The death of these young Africans at the borders of ‘Fortress Europe’ is a warning of the deadly nature of the security cooperation on immigration between Morocco and Spain," the statement added.

Spanish authorities in Melilla, meanwhile, are using the most recent attempt by migrants to cross over in mass numbers to make an appeal for even greater guarantees on their territorial security. Last year, when relations between Spain and Morocco were frayed, Moroccan border guard let thousands of people cross in a few hours in Ceuta, Spain’s other enclave city in Africa.

Since then, the Spanish media has been rife with debate about whether NATO would help Spain out if its hold of Melilla and Ceuta was ever in jeopardy.

"Melilla is Europe’s southern frontier, and that is why Europe must look to the south," Melilla chief Eduardo de Castro said Monday.