304 Dissidents Arrested Ahead of Obama's Cuba Visit: Rights Group

HAVANA, Cuba -- The head of Cuba's leading human rights organization tells ABC News that 304 people were arrested for criticizing the Cuban government just days before President Obama's historic visit to the island.

The Cuban Commission on Human Rights provided a list of names and the locations where the arrests took place -- 104 of them in Havana and others at locations throughout Cuba.

"Since last year, we're talking about thousands" of arrests, Elizardo Sanchez told ABC. "The worst thing is that the Cuban government has unleashed a huge wave of political oppression, and during Obama's visit this morning they were arresting people and this will go on for the rest of the day and probably tomorrow."

The crackdown underscores persistent challenges to freedom of speech and peaceful dissent inside Cuba, despite rapid normalization of diplomatic ties with the United States. The report also contrasts with Cuba President Raul Castro's insistence at a press conference Monday denying detention of any political opponents.

"We defend human rights," Castro said. "We oppose political manipulation and double standards in the approach to human rights."

Obama, who will meet with Sanchez and fellow activists Guillermo Farinas and Jose Daniel Ferrer Garcia on Tuesday, challenged Castro's assessment in real-time.

"I've met with people who have been subject to arbitrary detention," he said, "and that's something that I generally have to speak on because I hear from them directly and I know what it means for them."

ABC News visited the make-shift, and technically-outlawed office of the CCHR on a pothole-ridden street in the outskirts of Havana.

The men told ABC's Jonathan Karl that they intend to urge the president "not to let himself be manipulated" by the Castro regime.

"Every public or private space where he can be, sharing with ordinary citizens or the members of the government, he should mention words or phrases like, 'total respect of the decency of human rights,' 'multi-party system,' 'freedom of expression,' 'right to information,' 'freedom of conscience,' 'tolerance of ideas.'" Guillermo Farinas said.

"I believe that if Obama keeps mentioning those words publicly, the Cuban government will not look at him as complicit with the Cuban government but an ally of freedom," Farinas said.

Sanchez, Farinas and Garcia said they have spent a combined 27 years is Cuban prisons for speaking out against the regime.

"Under a government which imprisons any unjustly, the true place for a just man is also a prison," said Garcia, who has spent 8 1/2 years in prison and is still on parole. He told ABC he is not afraid of being arrested again for speaking to American media.

The activists said the human rights situation has actually gotten worse over the past year, with an increase in what they called "low-grade repression" -- short-term and arbitrary arrests of people seen as critical of the government. Most detentions usually last anywhere from a couple of hours to a few days.

In addition, there has been an increase in the number of political prisoners serving long-term sentences of several years.

The dissidents said the symbolism of their Obama meeting is incredibly important and plan to widely distribute photographs throughout Cuba.

"It will encourage people," Garcia said, "because it will tell many Cubans that you're not alone. And nothing paralyzes a Cuban more than making them feel that they are alone."

ABC News' Alex Mallin, Devin Dwyer, Hayley Walker and Gary Westphalen contributed to this report.