The leader of Ceuta demanded on Monday the detention and expulsion of the thousands of migrants wandering the Spanish north African territory's streets after last month's mass influx from Morocco.

Some 72,000 migrants breached the border in an unprecedented and deadly rush between 30-31 July, with 70,000 having since returned to Morocco, according to Spanish government figures.

But the thousands who remain, including hundreds of unaccompanied children who cannot be summarily deported, struggle to access food, water, shelter and sanitation while the tiny enclave's resources are overwhelmed.

Their future has sparked a political battle between Spain's leftist central government and regions governed by the main conservative Popular Party (PP) and far-right Vox, which resist taking in unaccompanied children under existing legal provisions.

"A space that acts as an internment centre for foreigners must be set up, where these people can be held and remain confined," Ceuta's PP leader Juan Jesús Vivas told reporters.