To proceed in such way, the Spanish government applied the constitution's article 155, which obliges autonomous communities to comply with Spanish laws in case their actions involve a "serious attack" against Spain's "general interest."
"Autonomous communities" are a form of political division which the 1978 constitution created so as to provide some level of self-government to different nationalities.
Currently, Spain has 17 autonomous communities, among which are the Basque country, Catalonia and other territories that have aspired to gain independence for centuries.
Besides warning pro-independence activists not to "play with fire," PM Sanchez condemned the Catalan protests held after the arrest of seven members of the Defense Committees of the Republic (CDR), an organization which supports the freedom of Catalan political prisoners.
Despite tacit threats steeming from Madrid, the Catalan regional president Quim Torra starred on Thuesday a public event in honor of the 2017 referendum and reaffirmed his commitment to move "without excuses" towards the creation of the "Catalan Republic".