Human Rights Watch (HRW) said on Thursday that Sudanese security forces have used threats, assaults and rape in order to silence female human rights activists.
HRW said Sudanese government officials have targeted mostly women activists involved in rights campaigns and protests including students, teachers, lawyers and journalists.
According to the rights group, violence and abuse of women increased in the country following the Arab Spring uprising, and especially after South Sudan's secession from Sudan in 2011 and Sudan's economic downturn.
"Sudanese women who defend human rights experience political repression like their male colleagues but are also vulnerable to sexual assault and intimidation because they are women," said HRW Africa director Daniel Bekele.
"Sudanese security officials often take advantage of discriminatory laws and social conventions to silence them," he added, speaking at the launch of HRW's report "Good Girls Don't Protest".
'You women activists and party members, you are all sharmuta [whores]'", said one activist, one of more than 85 female activists and human rights defenders interviewed by HRW.
"I said I work in what I believe. Then they started kicking me and one of them took his trousers off and started raping me."
The Sudanese government could not be reached for comment.
The civil war in South Sudan began in December 2013 after President Salvar Kiir accused his former deputy Riek Machar of attempting a failed coup.
Although more than 12,000 UN peacekeepers have been deployed in the country, at least 10,000 people have been killed so far while more than 2.3 million others have been forced to flee their homes while nearly 3.9 million face severe food shortages.