Thousands of protesters marched from Cibeles Square to the Moncloa Arch near the Spanish government headquarters on Saturday.
The protesters were demanding the resignation of the PM Pedro Sanchez due to his handling of the Ceuta migration crisis, and were also demanding new elections.
The city of Ceuta, a tiny speck of Spanish territory perched on the northern African coast, normally celebrates its Sept. 2 annual official holiday largely ignored by the mainland.
But not this year, after Ceuta became the epicenter of Spain's worst border crisis in living memory.
In late July, about 72,000 people swam, scrambled or charged into the small Spanish territory from neighboring Morocco, with at least 90 dying in the effort to reach Europe.
Most of the migrants quickly returned or were ushered back over the border, but around 5,000, including 1,200 minors, remain in Ceuta weeks later, according to the national government.
Ceuta's local government cited a higher figure. Difficult questions likewise linger over what caused the mass crossing that the government says was fueled by an online campaign on social media.
The sudden influx of tens of thousands of migrants into Ceuta, which has a population of about 84,000, put a huge strain on resources and angered many residents.
Local authorities said that Spain's central government ignored warning signs before the border was breached.
