Cuban police have put under house detention a second dissident who testified before the U.S. Senate last week, and arrested yet again the man who shouted “Down with communism” just before a mass by Pope Benedict XVI.

Havana human rights activist Elizardo Sánchez Santa Cruz said the arrests of more than 10 dissidents and police threats of more signaled a crackdown to block opposition plans for events to honor political prisoners on Fathers’ Day Sunday.

“We have confirmations of the arrests of several Ladies in White and other government opponents in the provinces of Villa Clara and Santiago de Cuba,” Sánchez told El Nuevo Herald by phone from Havana.

Dissident José Daniel Ferrer reported Tuesday that police were blocking the door to his house in Palmarito de Cauto in Santiago, threatening to arrest him if he leaves and telling him that he’s under investigation for a firebombing in a nearby town.

Residents of Palma Soriano have told dissidents that a Molotov cocktail exploded Sunday night in an empty field near a school, and another was found intact. State Security agents told the residents the blast could be the work of dissidents.

Ferrer said he is a peaceful government critic and had nothing to do with the firebomb. One of the 75 dissidents arrested in 2003, he was sentenced to 25 years in prison on charges of disseminating “enemy propapaganda.” He was freed last year as part of Cuban ruler Raúl Castro’s promise to free all political prisoners.

Ferrer and Jorge Luis García Perez, known as Antúnez, harshly criticized the Cuban government strongly Thursday when they testified before a subcommittee of the U.S. Senate Foreign Affairs Committee.

Antúnez was arrested Saturday, beaten and pepper sprayed in a police lockup in his hometown of Placetas in Villa Clara, according to his wife, Yris Tamara Pérez Aguilera. He was removed from the lockup that evening and has not been heard from since.

Police told her that Antúnez is being held in the provincial capital, Santa Clara, but when she and 12 other dissidents went to that police station Tuesday, they were arrested for several hours and then forced to go home without seeing him, the wife added.

If Antúnez was indeed there, it was odd that he did not join them in protesting when the 13 dissidents broke into chants of “down with the dictatorship,” Perez Aguilera told human rights activists in Miami.

The cell phones for Pérez Aguilera and several other dissidents in Villa Clara and Santiago appeared to have been blocked by authorities Tuesday so that they could not talk with supporters or journalists.

But Sen. John Kerry, D-Ma., chairman of the senate Foreign Relations committee, Tuesday joined the chorus of Cuban-American congress members who have condemned Antúnez arrest.

“I want to be crystal clear that I strongly condemn any efforts to intimidate Mr. Perez or any other Cuban citizen into silence,” said Kerry, considered a lead candidate to succeed Secretary of State Hilary Clinton if President Barack Obama wins reelection’

Andres Carrión, who was punched and dragged away after shouting anti-government slogans before Benedict’s mass in the city of Santiago de Cuba in March, was arrested Tuesday during a protest in a park to demand the return of personal property.

The freelance photographer was returning from Havana when police stopped him at a highway checkpoint outside the city and seized a new photo printer and other photo supplies, Sánchez said.

Carrión has been arrested several times since March, usually for brief periods. But police have warned him that they will put him on trial for “disobedience” if he continues criticizing the government and speaking with journalists.

Havana dissident Darsi Ferrer meanwhile announced that he will soon leave Cuba on a U.S. political asylum visa to join his wife Yusnaimy and young son Dariel in Chattanooga, Tennessee.

A physician, Ferrer has been particularly active in denouncing Cuba’s run-down health system, secretly filming videos of hospital rooms with broken doors and windows, bare electrical wires, bloody floors and bathrooms soiled with feces.

Sanchez said Ferrer wanted his wife to leave for the United States because she suffers from unspecified health issues. But authorities would not let her leave unless he agreed to leave also, he added.

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