More than 30 Cuban dissidents have been arrested in what analysts describe as the largest crackdown on the opposition movement in recent times.

The arrests began Tuesday night. By Wednesday afternoon, at least 35 people -- primarily, independent journalists and librarians -- had been taken into custody.

Some analysts linked the timing to the war in Iraq, when news of the arrests in the United States and elsewhere is likely to be overshadowed, if not ignored.

The librarians are private citizens who have turned their homes into reading rooms where Cuban citizens can read unauthorized, so-called ''counter-revolutionary'' literature. Among them are books by Martin Luther King and Vaclav Havel, and Animal Farm by George Orwell.

`ACT OF INTIMIDATION'

In Washington, State Department spokesman Richard Boucher described the arrests as ''an appalling act of intimidation'' and called on the international community and the United Nations Human Rights Commission, in particular, to condemn the action and demand immediate release of the detainees.

Most of those arrested have participated in activities organized by the U.S. Interests Section in Havana, including a gathering last week at the home of James Cason, the principal U.S. diplomat in Cuba.

The government blamed Cason for the arrests and accused him of trying to ''foment the internal counter-revolution.'' The detainees, the government said, were linked to ''conspiratorial acts'' carried out by Cason, whom Fidel Castro has called ``a bully with diplomatic immunity.''.

TV REPORT

In an unusual move, state-run television reported the detentions and said those in custody were being held for ''provocations'' and ''subversive activities.'' Cuba considers opponents on the island to be paid U.S. agents and the U.S. Interests Section a command post for activities aimed at dismantling the socialist system.

''Those measures are being taken against people who are working at the service of the United States,'' said Juan Hernández-Acén, a spokesman at the Cuban Interests Section in Washington. ``It's a proven fact that they are paid and act at the direction of the interests section.''

''The United States has taken similar measures against people they consider to be risks to national security, isn't that so?,'' Hernández-Acén added.

``Cason has given them financial support and equipment.''

The gathering at Cason's home involved 34 independent Cuban journalists who took part in a workshop on ethics. Last month, Cason drew verbal wrath from the Cuban government when he attended a meeting of about 40 dissidents at the home Martha Beatriz Roque and declared that Cuba was ''afraid'' of freedom of conscience, expression and human rights.

INVITATION

Roque, who is on a hunger strike to call attention to the plight of political prisoners, could not be reached for comment Wednesday. But in a written statement sent to The Herald, she said: ``Yes, I invited Cason, but also diplomats from the European Union, Canada and Chile. The only one who challenged the government was Cason. I invited them all because diplomats interact with civil society in all countries.''

Following Cason's remarks, Castro warned that he might be forced to shut down the interests section.

Other government opponents described the crackdown as an act of terror and said the Cuban government had succeeded in creating a sense of fear.

''People are scared,'' prominent dissident Vladimiro Roca, who was released from jail last year after serving nearly five years on charges of sedition, said Wednesday by phone. ``I see this as an act to terrify the people and dissidents who are trying to find a solution to this situation through peaceful means.''

MORE ARRESTS

''I think the detentions will continue and there will be more reprisals,'' Roca said, adding that he would not be surprised if authorities arrested him as well. ``The government has proven that when it's decided to carry out a terrorist campaign like this, there's nothing that can stop it.''

Besides Cason's actions, a number of other incidents have contributed to the increasingly strained relations between the U.S. and Cuba, including:

• A public endorsement by Secretary of State Colin Powell in January of leading Cuban dissident Oswaldo Payá, coordinator of a petition drive seeking democratic reforms.

• Last month's release of a State Department report accusing Cuba of a harassment campaign against diplomats in Havana involving vandalism, surveillance, sexual entrapment and petty crimes.

• The White House's use of a veto threat in February that succeeded in stripping language in a spending bill that would have eased the four-decades-old U.S. embargo on Cuba.

Antonio Jorge, a professor of economics and international relations at Florida International University and an expert on Cuba, said the crackdown is a typical Fidel Castro tactic.

''He's using this as a bargaining chip so he can get concessions such as a relaxation in the travel ban,'' Jorge said.

Herald writer Larissa Ruiz Campo contributed to this report.