Occasional clashes broke out between riot police and protesters as the large crowds pushed against police cordons, La Vanguardia reports.
The separatist parties failed to elect a new regional president on March 23 after their most radical faction refused to back Turull in a vote of confidence.A second round parliamentary vote was due to take place on March 24.
Spain's Supreme Court ruled 25 Catalan leaders should be tried for rebellion, embezzlement or disobeying the state.
If he returns to Spain, Puigdemont faces up to 25 years in prison on charges of rebellion and sedition for his part in organising an illegal referendum on secession last year.
Former Catalan leader Carles Puigdemont faces arrest in Finland after authorities there received an worldwide warrant for his detention issued by Spain, the latest legal action against separatist politicians from the wealthy northeastern region.
Judge Llarena also issued an arrest warrant for Marta Rovira, the deputy head of the separatist Esquerra Republicana party, who failed to appear in court on Friday.
The five Catalan politicians remanded in custody on Friday were: (1) Jordi Turull - former Catalan government spokesman and the latest candidate for regional president, (2) Josep Rull - former Catalan development minister, (3) Carme Forcadell - former Catalan parliament speaker, (4) Raul Romeva - former Catalan foreign affairs chief and (5) Dolors Bassa - former Catalan labour minister.
Llarena said the five detainees posed a serious flight risk and could seek to push ahead with their plans for unilateral independence if allowed to remain at liberty.
More news: Alibaba to invest additional 1.44 billion pounds in Lazada, replaces CEOThe unity of Spain is enshrined in the Constitution, which says the country is "indivisible", and courts have blocked Catalonia's independence efforts at every turn.
Judge Llarena is reactivating an arrest warrant that he dropped a year ago against Mr. Puigdemont and other former members of his cabinet, amid concerns that courts in Belgium, where he fled, would instead soften the charges against them.
The five join four other Catalan leaders already detained in prison.
"The [parliamentary] session has been canceled", speaker of the Catalan parliament Roger Torrent said at the session's opening.
A date for the trial has yet to be announced.
Spanish Prime Minister Mariano Rajoy had in December called for snap elections in Catalonia.
This would entail fewer calls for engagement with Madrid and the heightening tensions between the regional and federal governments.
Wild protests have erupted in the Basque region of Barcelona after a Spanish High Court detained five Catalan politicians for their role in the region's secessionist bid staged in October previous year. If a second investiture debate happens today, Mr Turull would only need a simple majority to assume the presidency.
