Human rights activist Elizardo Sanchez, in Havana, described the action Wednesday as "short-term, arbitrary detentions for political motives."
Although most detainees were released later in the day, the scope of the police action suggested the Cuban government is turning to tougher and more violent means of repression.
A journalist, Roberto de Jesus Guerra, claimed a Cuban State Security plainclothes agent attacked him as he walked to the Czech embassy in Havana to use its Internet connection. He later said in an interview, "I am going to the doctor now and later to the police to file a complaint, although they never do anything because they are the ones beating us."
Prominent dissidents Jorge Luis García Pérez, known as Antúnez, and his wife, Yris Pérez Aguilera, were taken from their home in Placetas. Also among those detained were Berta Soler, leader of the Ladies in White protest movement, and her husband, Angel Moya, a dissident who previously served eight years in prison.
Sanchez's group, the Cuban Committee for Human Rights and National Reconciliation, said there have been 3,821 such detentions in the first four months of 2014, a higher figure than usual. The detentions are meant to intimidate dissidents and discourage gatherings that ferment protest.