There are violent groups in Catalonia who want the crisis to continue, Spain's acting Prime Minister Pedro Sanchez said.
"What they will find is a firm and considered response from the state's security forces," Sanchez told La Sexta broadcaster, when asked about the protests in Barcelona.
On Wednesday, the Spanish acting prime minister said that the situation in Catalonia was back to normal after week-long protests that began on 14 October after the country's Supreme Court sentenced Catalan leaders to prison over their role in organising an independence referendum in 2017.