"We demand from the Spanish government to break off diplomatic relations with the government of Ukraine," Angeles Maestro, spokeswoman for the Forum Against Imperialist War and NATO told Sputnik.
The demonstration started because of the rapid escalation in the east of Ukraine. Spanish activists put the blame on the government of Ukraine, claiming that Kiev have "started a punitive operation against the civilian population of Donbas, violating the Minsk agreements that call to end the use of heavy weapons," Maestro explained.
"We blame the European Union for aiding the government created in a coup and supported by the people with Nazi views," she stated.
The activists, holding signs "Donbass Will Win!" and "Fascism Go Away From Donbass!", called for the Spanish government to "stop political and military support, both direct and indirect, through the EU and NATO, for the criminal government in Kiev".
"We as internationalists and anti-fascist want to express our support to Donbass. We remember that Madrid owes the Ukrainians that came to Spain to fight against the Francoism during the Civil War [1936-1939]," Maestro added.
The news comes as the Ukrainian forces resumed heavy shelling of the residential areas of Donetsk on Sunday, deploying additional troops closer to the borders of the self-proclaimed republics in the east of the country.
The breakout of hostilities in eastern Ukraine began in April 2014 as a local counter-reaction to the West-sponsored Maidan coup in Kiev that had toppled legitimate President Viktor Yanukovych in February. Residents of the Donetsk and Lugansk regions held independence referendums and proclaimed the People's Republics of Donetsk and Lugansk. Kiev has since been conducting a military operation, encountering stiff local resistance.