Visitors to Barcelona are being warned of demonstrations in the city that could disrupt travel.
Protests have been held in Barcelona and in other parts of Spain’s Catalonia region since Wednesday.
Supporters of Catalan independence are protesting against the Spanish government’s decision to ban an independence referendum on October 1.
The Spanish government has since ordered police raids on key Catalan government buildings to seize documents related to the vote and Catalan officials have been arrested.
Thousands of independence supporters have been gathering in front of the high court in Barcelona and are threatening to continue until the officials are freed.
The UK Foreign Office said the protests could continue for some days and could cause some disruption and delays to transport services.
