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.