Attempts by authorities in the Democratic Republic of Congo to crack down on dissent during tense vote counting could "backfire", the UN said on Friday, warning it was "watching carefully" as events unfold. Elections held last Sunday will determine who succeeds President Joseph Kabila, at the helm of sub-Saharan Africa's biggest country for nearly 18 years.Authorities have restricted internet access, blocked French public-service broadcaster Radio France Internationale and forced its correspondent out of the country. "This being a very sensitive, very tense period, we are concerned that these efforts to silence dissent could backfire considerably when the results are announced," a spokeswoman for the United Nations Human Rights office, Ravina Shamdasani, told reporters in Geneva. "We are watching carefully and we are calling on all sides to refrain from the use of violence," she added. Opposition fears are running high that the result will be rigged to favour Kabila's preferred successor, Emmanuel Ramazani Shadary.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. The Congolese election commission said Thursday that logistical problems may force it to postpone publication of provisional results, which are due by Sunday.But the DRC's powerful Roman Catholic Church, which deployed thousands of election observers, said it knew who had won and urged the electoral panel to publish the "truth". The DRC's minister for higher education, Steve Mbikayi, on Friday said the country's universities would reopen on January 14 after the year-end break, a week later than scheduled, because of election tensions."Every time that presidential election results are published, regardless of which side who wins, there is always one side which is dissatisfied and wants to exploit the students," Mbikayi told AFP in Kinshasa."I think that they can stay at home and return after publication (of the results), to shield them from any temptation or manipulation."Elections to the national parliament and provincial assemblies took place alongside the presidential ballot.