A report from human rights group Amnesty International has accused Cuba of instituting "a climate of fear that stifles and criminalises dissent" against the island's communist government.
According to the report, which was released on Wednesday, Cuban laws are so vague and arbitrary that any act of dissent can be deemed criminal.
The Cuban government has not issued an official response to the report, but it routinely dismisses international human rights groups as tools of the United States.
Amnesty has said it gathered information from independent sources on and off the island, but conducted no first-hand research because it has been banned from Cuba since 1990.
The report said that although Cuba signed the International Covenant on Civil and Political Rights in February 2008, there has been no improvement in rights for Cuban citizens.
It noted also that independent Cuban journalists continue to face a wide range of restrictions and repression while attempting to report in defiance of state controls on all media.
"There is certainly a wave, we would call it, of harassment and arbitrary detention of independent journalists at the moment,'' Kerrie Howard, Amnesty International's deputy director for the Americas, told the Associated Press in the Spanish capital Madrid where the report was released.
According to Amnesty, the Cuban government has launched crackdowns on individual liberties in the name of national security and in response to Washington's 48-year-old trade sanctions against the country.
|Guillermo Farinas, another activist, went on a hunger strike following Tamayo's death [EPA]
"No matter how detrimental its impact, the US embargo is a lame excuse for violating the rights of citizens, as it can in no way diminish the obligation on the Cuban government to protect, respect and fulfil the human rights of all Cubans,'' the report said.
Cuba's human rights situation has been in the spotlight since the death of dissident Orlando Zapata Tamayo in February after a long hunger strike behind bars.
Tamayo had been designated as a "prisoner of conscience" by Amnesty.
Guillermo Farinas, another opposition activist, has refused to eat or drink since then, although he has received fluids and nutrients intravenously at a hospital near his home in central Cuba.
The Cuban government insists that it holds no political prisoners and safeguards human rights by providing citizens with free education and health care, as well as heavily subsidised housing, utilities, transportation and food.