Dozens of people have been arrested in Cuba after thousands joined the biggest protests for decades against the island's Communist government, media and opposition sources say. Unauthorised public gatherings are illegal in Cuba and protests are rare. Images on social media showed what appeared to be security forces detaining, beating and pepper-spraying some of the protesters. Cuba's president labelled those protesting "mercenaries". In a four-hour-long televised address President Miguel Díaz-Canel slammed protestors as "counter-revolutionaries" while his foreign minister alleged the demonstrations had been financed and instigated by the United States. But those who took to the streets said they were angry about the collapse of the economy, food and medicine shortages, price hikes and the government's handling of Covid-19. The government's response to the demonstrations was swift. Figures compiled by legal help centre Cubalex suggest around 100 people were arrested on Sunday. Among those detained is journalist Camila Acosta who was covering the protests for Spanish newspaper ABC. Spanish Foreign Minister José Manuel Albares demanded her immediate release. A young man who only gave his name as Carlos Alberto told BBC News Mundo he was hiding at his girlfriend's home after taking part in a demonstration. "A colleague of mine was arrested, they came to look for him at his home. I'm afraid the same thing could happen to me," he said. "We weren't doing anything bad, we're just asking for freedom and with this attitude they're showing what they are: a dictatorship," he told BBC Mundo's Lioman Lima over the phone.