Carrying through on promises to halt the upcoming independence referendum, a dozen top Catalan government officials were detained following the raiding of regional government offices by the Madrid state, according to La Vanguardia.
The Catalan government was able to confirm that Catalonia's junior economy minister was among the arrested.
Police have confirmed that they were carrying out the raids, but declined to provide details.
Hundreds gathered outside government offices in Barcelona to protest the crack-down, chanting “We will vote,” Reuters reported.
The government spokesperson of Catalonia, Jordi Turull, urged calmness in the face of what he called the “police and siege state,” and said that the referendum will go on, La Vanguardia reported.
The Vice President of Catalonia, Oriol Junqueras, said that the Madrid-based Spanish government is exhibiting “a total contempt toward the will of the people.”
The left-wing Podemos leader, Pablo Iglesias, said that Spain is heading toward a situation in which they will have "political prisoners," El Pais reported.
The Catalonian leader, Carles Puigdemont, called an emergency meeting of his cabinet for later on Wednesday.
Among the buildings raided were the foreign affairs, telecommunications, social affairs, and presidential buildings, which were searched for computer equipment and documentation pertaining to the planned October 1st referendum.
On Tuesday, Spanish police seized nearly 50,000 envelopes with the Catalan government's logo from a delivery company, which were going to be used to deliver ballot materials.
The government has also opened a legal investigation into over 700 Catalan local mayors, who have said they will allow the referendum to continue in their municipalities. The first of these were forced to appear before a court on Tuesday.
Since the independence referendum for Catalonia, whose capital is Barcelona, was called earlier this month, the Spanish government has fiercely opposed the measure, which they say is illegal.