Spain’s prime minister, Pedro Sánchez, has called for an urgent meeting of EU interior ministers after what he called some member states’ “selfish, polarising and unlawful reaction” to this week’s mass border crossing into the Spanish enclave of Ceuta, in north Africa.

More than 50,000 people crossed into the territory from Morocco on Thursday and Friday, with at least 67 people dying in the attempt. Some drowned, while others were crushed as they tried to cross a breakwater barrier.

Although more than 48,000 people had voluntarily returned to Morocco by 6pm on Friday, the influx triggered a political crisis for the Madrid government and led some fellow EU countries to call for Spain to be suspended from the Schengen free-movement zone.

Sánchez confirmed “virtually all” of those who had crossed the border had been returned, “preventing any unauthorised onward movement towards continental Europe”.

However, he asked for the meeting after what appeared to be a breakdown of EU unity on external border policy, with Italy attacking Spain.

Italy announced on Friday evening that it would suspend its Schengen arrangements with Spain for a month, even though Ceuta – and Spain’s other north African enclave, Melilla – are subject to special Schengen rules that prevent onward movement within the zone.

Italy’s foreign minister, Antonio Tajani, blamed the situation in Ceuta on the Sánchez government’s decision to offer a now-closed scheme to regularise the status of more than 1 million undocumented migrants and asylum seekers. He said the programme had incentivised human trafficking and was “profoundly wrong”.

Sánchez was forthright in a letter sent to the European Commission president, Ursula von der Leyen, the European Council president, António Costa, and Micheál Martin, the prime minister of Ireland, which holds the EU presidency.

Sánchez said that while most EU countries had expressed support and solidarity over events in Ceuta, others had chosen to attack Spain.

“Such an attitude – driven by prejudice, fake news, ignorance or political interest – is … contrary to European law, humanitarian law, and the principles of solidarity that bind us together,” he said.

In a pointed rebuke to Italy, he noted that Spain was “according to Frontex, one of the least porous external borders of the European Union, with a number of irregular entries that is half that recorded, for example, in Italy in recent years (2021–2026)”.

He concluded by saying the EU could not afford “this kind of selfish, polarising and unlawful reaction” and asked for an urgent video conference of EU interior ministers to address the issue.

Senior EU officials are due to meet on Saturday in a “political crisis response team” convened by Ireland’s presidency.

Ireland’s justice minister, Jim O’Callaghan, who is leading the meeting on behalf of the EU, said he had been in touch with Spain’s interior minister, Fernando Grande-Marlaska, to express his solidarity and support.

“I will remain in close contact with the Spanish government, member states and the EU institutions as the situation evolves,” he said on Friday night.

France’s interior minister, Laurent Nuñez, said his country would not be seeking Spain’s suspension from Schengen rules.

“It’s absolutely not on the table,” he said on Saturday. “We have great cooperation with Spain.”

Many of the remaining people who crossed into Ceuta returned to Morocco on Saturday morning amid a reinforced Spanish police and military presence.

“We hope to go to Europe to work and earn a living – that’s it,” Souleil Boyan, a 19-year-old from Senegal, told Agence France-Presse outside a migrant centre in Ceuta where dozens of other people from sub-Saharan Africa were waiting for officials.

“We all know that in Africa there isn’t much opportunity,” he added.

The Spanish government said in a statement on Saturday that the situation in Ceuta remained calm and quiet.

“Friday night passed without incident,” it said. “Entries were completely halted, while departures to Morocco continued without any notable events.”

It said containment barriers were being installed at the Tarajal beach breakwater, including a 500-metre-long inflatable barrier and a line of anchored buoys.

This week’s mass crossing dwarfs the last similar event in May 2021, when Morocco loosened its border controls, allowing about 10,000 people to enter the territory over two days.

That crossing came amid heightened tensions between Madrid and Rabat over Spain’s decision to allow the leader of the Western Sahara independence movement, the Polisario Front, to be treated for Covid-19 in Spain. Morocco and the Polisario Front both lay claim to Western Sahara, which was under Spanish rule until 1975, when colonial authorities handed over the territory to Morocco and Mauritania.

That diplomatic crisis ended in 2022 when Madrid reversed its longstanding policy of neutrality and backed Morocco’s plan for Western Sahara, a move that caused a rift between Spain and Algeria, which had supported the Polisario group.

Sánchez visited Algiers on 20 July – the first visit by a Spanish head of government in four years – marking a thaw in relations with Algeria.

The Spanish government has attributed the latest influx to “human-trafficking mafias” that have taken advantage of a decision by Spain’s supreme court, which recently ruled that those intercepted at sea while trying to enter Ceuta or Melilla could not be summarily returned under special rules.

But some migration experts have expressed doubts about that explanation. Mauricio Valiente, the director general of the Spanish Refugee Aid Commission, said the route into Ceuta was very different from the Atlantic route from Africa to the Canary Islands, which is often operated by people smugglers.

“Unlike what happens in the Canary Islands, these aren’t people who have to get into a small boat,” he told elDiario.es. “This is a matter of being just metres from a land border, jumping into the sea and trying to get around a breakwater, which makes it much easier to do, even with all the risks.”

Valiente said there had been a steady increase in arrivals to Ceuta this year, even before the supreme court ruling.

“The causes are complex, and there are surely many reasons,” he said. “But to simplify it by referencing the court ruling or organised crime – to say there’s a direct cause-and-effect relationship – is completely unfounded.”