By Danny Wood
BBC News, Madrid
Authorities in Spain's Canary Islands have raised concerns over 700 unaccompanied children who have arrived by boat.
The Canary Islands authorities say 700 children have arrived recently
The children have arrived among thousands of illegal immigrants.
The Canaries have received 4,500 mainly African migrants this month - nearly as many as for the whole of last year.
The Canary Islands says it does not have the resources to care properly for the children - and wants the rest of Spain and the European Union to help.
The local authority says it now has more under-age migrants than Spaniards in custodial care.
The regional president Adan Martin says with the Canaries overburdened by an immigration avalanche, it's dangerous for his administration to have responsibility for the upbringing of these minors.
Under Spanish law, the Canary Islands is obliged to care for and educate these young arrivals until they reach the age of 18.
The authorities in the Canaries have called on Spain's government and the European Union to share responsibility for these children.
Thousands of migrants have arrived in the Canaries this year
More than 18,000 illegal immigrants have arrived on the islands by boat this year. Detention centres in the Canaries only have capacity for about 5,500.
To cope with the overflow, the national government has transferred thousands to the mainland. As a result, Red Cross shelters in Madrid are full.
The Conservative Popular Party claims the government is washing its hands of the immigration problem by sending most of the migrants to regions administered by the opposition.
But the leader of the Canary Islands, Mr Martin, says Spanish regions questioning this policy of redistribution do not understand. Mr Martin says these illegal arrivals are not the Canaries' migrants, they are Spain's and Europe's.