Human Rights Watch says a climate of fear threatens the Democratic Republic of Congo's first elections in 40 years.
The New York-based rights group says there was an increase in the number of attacks and detentions of journalists, human rights defenders and members of the political opposition in April and May.
Human Rights Watch said Congolese authorities have failed to provide protection to the groups, and charged that security forces were involved in some of the attacks.
The rights group urged a U.N. Security Council delegation set to visit the DRC Sunday to speak out against the intimidation.
It said the elections, set for July 30, cannot be free and fair if the press and civil society are too afraid to speak out or engage in legitimate political debate.
The DRC has been struggling to recover from a five-year civil war that left an estimated four million people dead.
Some information for this report was provided by Reuters.