The leader of Spain's north African territory of Ceuta on Wednesday said the number of children left there after last week's rush of migrants was "unsustainable", pleading for government aid.
Spain says 70,000 of the 72,000 migrants who entered Ceuta from Morocco have returned, after the deadly influx sparked a spat with EU partners seeking a harder line on immigration.
But the roughly 2,500 who remain include hundreds of unaccompanied minors who are enduring dire conditions with limited access to food, water, shelter and sanitation.
Ceuta's leader Juan Jesus Vivas, of the main opposition conservative Popular Party (PP), told public broadcaster RTVE that authorities were taking care of 1,100 youngsters against a theoretical capacity of 90.
"This is an absolutely unsustainable situation," said Vivas, adding that there was "a high risk for order and public security" as reception centres were overwhelmed.
Groups of young migrants continued to roam the streets of Ceuta on Wednesday, gathering in parks and beaches as authorities worked to identify and accommodate them, an AFP reporter saw.
The Spanish government's top official in Ceuta, Miguel Angel Perez, conceded those youngsters were "a priority, a source of great concern".
The charity Save the Children estimates that around 1,000 "unprotected" minors are among the migrants still in Ceuta.
"We are asking for help, for assistance from the rest of Spain" through the leftist central government, said Vivas.
Any redistribution of the children to the rest of Spain under existing legal provisions is likely to meet resistance from regions governed by the PP and the anti-immigration, far-right Vox party.
Socialist deputy prime minister Carlos Cuerpo insisted on public television that the PP and its regional governments "must comply with the law just like everyone else".
The ministry for youth and children has announced 25 million euros ($29 million) of emergency funding for Ceuta to help the tiny territory of 84,000 inhabitants to care for the minors.
Spanish legal authorities raised the death toll from last week's incident to 78 after a body was recovered late on Wednesday.
Morocco's interior ministry on Sunday said 11 people had died on the Moroccan side of the border, all but one by drowning as they tried to swim around a barrier in the Mediterranean Sea.
Vivas said he had contacted Prime Minister Pedro Sanchez's office on July 27 to warn that hundreds of migrants had entered Ceuta from Morocco and "we were headed for serious trouble".
The office said it would get in touch with "the relevant ministries" to address the matter, he added.
The following day Vivas said he asked the interior ministry to declare a national state of emergency but was told this was "not legally possible".
"We gave sufficient warning that the situation was becoming extremely strained and that exceptional measures needed to be adopted," he added.
The government has maintained that it received no prior warning of the scale of the incident.