BARCELONA, Spain — The government of Catalonia accused the Spanish government in Madrid on Tuesday of destroying any chance of dialogue after a judge ordered the arrest of two of the main leaders of the separatist movement.
Jordi Turull, a spokesman for the Catalan government, told Catalunya Radio, a Barcelona-based station, that the Spanish state had “dynamited” the proposal for talks made by Carles Puigdemont, Catalonia’s separatist leader. Mr. Puigdemont wrote a letter on Monday to Prime Minister Mariano Rajoy asking for negotiations to find a solution to the territorial conflict, but without clarifying whether he had declared independence from Spain.
On Tuesday night, some 200,000 demonstrators gathered in central Barcelona, according to the local police. They held candles and shouted “freedom” at the start of the protest, which was convened to demand the release of the two jailed separatist leaders. The demonstrators then stood in silence, raising signs addressed to the European Union that read, “Help Catalonia.”
Similar demonstrations were held in other cities in the region, and the Catalan independence movement plans to hold another in Barcelona on Saturday afternoon.
The separatists have called the arrests of the two leaders, Jordi Cuixart and Jordi Sanchez, politically motivated.
Rafael Catalá, the Spanish justice minister, told a news conference on Tuesday morning that the separatists were misrepresenting the court decision. He said the two Catalan leaders could be described as “imprisoned politicians” but not as “political prisoners.”
Mr. Cuixart and Mr. Sanchez spent Monday night in a Madrid jail after a judge ordered that they be held without bail while the authorities determined whether to charge them with sedition.
Prosecutors have accused Mr. Sanchez and Mr. Cuixart of leading protestson Sept. 20 during which officers from the Spanish national police were trapped for hours inside a Catalan government building by thousands of demonstrators. Officers had raided the building to arrest officials on charges of having organized an illegal referendum on independence. No one was injured, but protesters damaged Spanish police cars parked outside the building.
Fernando Martínez Maillo, a senior official of the governing Popular Party in Spain, said on national television on Tuesday that the judge had made “normal judicial decisions” in a country where “there is no impunity.” He denied that the arrests were politically motivated, saying, “I am very proud of a country where there is separation of powers.”
“Does anybody really think that if you destroy a police car, nothing then happens?” Mr. Martínez Maillo said. “There is an attempt to portray Spain as a repressive country, which leads to nowhere and doesn’t represent reality.”
On Monday, the judge, Carmen Lamela, from Spain’s national court, also questioned for a second time the Catalan police chief, Josep Lluís Trapero, about why his officers had not been able to stop a protest in September and why they had failed to close polling stations before voting started, as ordered by Madrid.
But Judge Lamela rejected the prosecution’s demand that the police chief be held without bail pending a trial, and on Tuesday morning Mr. Trapero returned to his police headquarters, where he was received with applause by a crowd of officers and other colleagues.
The Catalan independence referendum on Oct. 1, which was marred by violent clashes between voters and the national police, was held despite being suspended by Spain’s constitutional court. On Tuesday, the court’s judges confirmed unanimously that the Catalan vote had been held in violation of Spain’s Constitution.
The Madrid government had asked Mr. Puigdemont to clarify by Thursday morning whether he had declared Catalonia’s independence on Oct. 10 during a confusing address to Catalan lawmakers. Mr. Rajoy said last week that, without such a clarification, he would use Madrid’s emergency powers to take administrative control of Catalonia.
It is unclear exactly how Mr. Rajoy would intervene in Catalonia. The emergency powers at his disposal are significant but ill defined, and their use has no precedent.
For Mr. Puigdemont, the challenge now is to keep his unwieldy coalition of separatist lawmakers together amid growing pressure from hard-line politicians who want him to make a clean break with Madrid. The separatist coalition controls 72 of the 135 seats in the Catalan Parliament, but its parties differ fundamentally on social and economic issues.
Jordi Xucla, a lawmaker from Mr. Puigdemont’s conservative party, said on Tuesday that the party would not take part in a planned Spanish commission to reform the Constitution, following the arrest of Mr. Cuixart and Mr. Sanchez. Mr. Rajoy and Pedro Sánchez, the leader of Spain’s main opposition party, agreed last week to set up such a commission as a first step toward overhauling the Constitution, which was approved in 1978.
Mireia Boya, a politician from the Popular Unity Candidacy, a far-left party that has long pushed for secession, told reporters on Tuesday that Catalonia would confirm its independence in the coming days.
After Monday’s detentions, the creation of a Catalan republic could no longer be only a desire, she said, but “a basic necessity to guarantee fundamental rights.”