GENEVA Sudanese authorities have restricted press freedom and made arbitrary arrests ahead of a referendum on Sunday expected to endorse secession by south Sudan, the United Nations human rights chief said on Thursday.
High Commissioner for Human Rights Navi Pillay, a former U.N. war crimes judge, also voiced concern that some Sudanese officials had made inflammatory remarks about the future of more than 1.5 million southerners living in the north.
In a statement, she urged authorities to guarantee that voters' rights are not violated before, during or after the referendum and that its outcome is credible.
"This is a critical moment in Sudan's history," said Pillay, who is from South Africa.
"It is essential that the vote is free and fair, and that the national government and the government of South Sudan take swift and effective measures to halt any attempts to intimidate any groups or individuals, or to subvert the result."
She welcomed Khartoum's pledge to respect the outcome of the referendum, which is expected to lead to secession under a 2005 north-south peace deal that ended Africa's longest civil war.
"Nevertheless, the run-up to the referendum has been marked by some worrying trends, including restrictions in press freedom and a number of arbitrary arrests and detention. Both governments must ensure that these problems do not re-emerge over the next few days and weeks," she said.
Her office had no immediate details on the number of arrests but said that they had taken place in both the north and the south.
"I have been particularly concerned by reports that state officials have made provocative statements about the future of Southern Sudanese living in the North.
"Officials in both the North and South should refrain from inflammatory remarks, and instead -- whichever way the result goes -- work for a secure, peaceful and prosperous future for all Sudanese," she said.
Millions of southerners fled to the north to escape fighting during the decades of conflict. Ahead of the vote, tens of thousands of them have already sold their homes and made the difficult return journey south, drawn by promises of a better life and driven by fears about their citizenship rights in a divided Sudan.
A new oil-sharing deal between the northern and southern governments must ensure transparency and independent monitoring to avoid mistrust that could fuel future conflict, resource campaign group Global Witness said on Thursday.