Cuba's communist government freed writer Raul Rivero (search) and another dissident from prison Tuesday, the latest in a series of releases apparently aimed at cleaning up the island's human rights record.

Rivero, among 75 dissidents rounded up in a massive crackdown in March 2003, had been sentenced to 20 years in prison on charges of working with the United States to undermine Fidel Castro's socialist government. Rivero and the other activists denied the charges.

Also freed Tuesday was opposition party member Osvaldo Alfonso Valdes (search), 39, who was also among the original 75 and had been sentenced to 18 years in prison.

"I don't have any plans for the future," Rivero said after he arrived at his Havana home. "I'm still confused."

Rivero's wife, Blanca Reyes, said her husband was released on a medical parole after a checkup at a Havana prison hospital for emphysema and cysts on a kidney.

The dissidents released Monday also suffered medical ailments. Economics writer Oscar Espinosa Chepe (search) was hospitalized for months with a liver ailment, Marcelo Lopez (search) has a neurological disorder and Margarito Broche (search) suffered a heart attack behind bars in August.

Castro's government made no public statement about the releases, but analysts said the government was eager to avoid the possibility the dissidents would die in jail, and to signal flexibility to the European Union and Spain amid warming relations.

The latest releases come just days after Cuban Foreign Minister Felipe Perez Roque announced his country has resumed formal contacts with Spain, although that country had repeatedly criticized last year's dissident crackdown.

The new Socialist government of Spanish Prime Minister Jose Luis Rodriguez Zapatero (search) has said all Spanish political parties and the European Union should work to encourage the Caribbean island to open up.

"It's a step in the right direction," said Javier Valenzuela, spokesman for Zapatero, who on Tuesday was attending a one-day summit with Italian Prime Minister Silvio Berlusconi in Cuenca, Spain.

"We think this has to do with the Spanish government: firmness in its principles while proposing more efficient tactics in its relations with Cuba," Valenzuela said. "The liberation of a dissident is always a reason for joy for any democrat."

International human rights groups, however, called on Castro's government to free the dozens of others still behind bars.

"Cuba's release of these political prisoners is a welcome move, but many more remain incarcerated in violation of their fundamental rights," said Jose Miguel Vivanco, Americas director at Human Rights Watch (search). "We call on the Cuban authorities to release all of them."

Vivanco regretted that the three men released Monday were freed on parole, rather than unconditionally.

"By granting them parole only, the Cuban government leaves open the possibility of returning the dissidents to prison to serve out their sentences in the future," said Vivanco. "Its a way of intimidating them from exercising their fundamental rights."

The New York-based Committee to Protect Journalists (search) said it welcomed the release of Espionsa Chepe, one of more than two dozen independent Cuban journalists jailed on the communist-run island.

"Their only offense was doing their jobs," said the committee's Executive Director Ann Cooper. "We again call on Cuban authorities to immediately and unconditionally release all imprisoned journalists, and to allow them to work freely."

After his release, Espinosa Chepe spoke from his book-filled living room, where a small Christmas tree sat atop a refrigerator in the corner. He said he hoped the rest of the prisoners would return home.

"We are nonviolent people, who have not committed any crimes," he said.

Despite the difficulties suffered in jail, Espinosa Chepe said he did not want to leave Cuba. "I feel Cuban and I want to die in my own country," he said.

In Washington, State Department spokesman Richard Boucher welcomed the releases but said the detainees never should have been imprisoned in the first place.

"We continue to condemn the unjust incarceration of dozens of other prisoners of conscience in Cuba," Boucher said. "We hope that they can return to their work to build a truly just and open Cuban society."