Spain accuses Morocco of 'aggression' and 'blackmail'
"It is an aggression of Spanish borders and of the borders of the European Union, and this, in international law is unacceptable," Margarita Robles said during an interview with Spanish public radio, adding that Rabat was "using" minors.
"We are not talking about youths aged 16, 17, children as young as 7 or 8 were allowed through according to NGOs... ignoring international law."
"Call it what you want but I call it blackmail," the minister added.
"It is not acceptable to put the lives of minors or of people of one's own country, at risk for reasons that I don't understand."
Several Spanish and Moroccan NGOs have expressed concern over the huge number of minors who have crossed over into Ceuta from Morocco, and the fact that Madrid is sending them back.
Over 8,000 people, a record, crossed into Ceuta by swimming or on small inflatable boats from neighbouring Morocco, prompting a crisis between Rabat and Madrid.
The majority were Moroccans and they included families with small children and many teenagers on their own.
Around 5,600 migrants had already been sent back according to the Spanish government, which said there were no new entries on Wednesday as anyone who reached Ceuta's beach was immediately sent back.
Analysts said it was clear Morocco had turned a blind eye to the human tide entering Ceuta in order to put diplomatic pressure on Spain to recognise its sovereignty over Western Sahara.
The influx comes against the backdrop of increased tensions with Morocco over Spain's decision to provide medical treatment for the leader of the Polisario Front. The head of the Western Sahara independence movement has been seriously ill with Covid-19.
The Front has fought for the independence of Western Sahara, a former Spanish colony mainly under Moroccan control.
Morocco's minister of state for human rights, Mustapha Ramid, said Wednesday it was "clear" Spain had favoured its ties with the Polisario and Algeria over those with Morocco by hosting Ghali.
"Spain must also know that the price for discrediting Morocco is steep," he added in a Facebook post.