ABIDJAN - International mediators Monday urged a peaceful end to a political crisis in Ivory Coast amid the threat of unrest and growing world pressure on the two powerful rivals claiming the presidency.
The United Nations said it was pulling hundreds of staff out of the country due to the volatile situation, as South African ex-president Thabo Mbeki ended an urgent mediation mission without any major announcement after talks with the rivals.
At least 20 people have been killed in election-related violence since the disputed presidential vote on November 28, human rights organisation Amnesty International said Monday.
UN Secretary General Ban Ki-moon "remains deeply concerned" and "has been in close contact with many world leaders," spokesman Farhan Haq said.
The European Union meanwhile threatened sanctions if the crisis is not resolved fast.
Clinging to power, incumbent Laurent Gbagbo extended a nightly curfew to curb disturbances, state television said, as the country waited tensely for a break in the deadlock between him and his rival Alassane Ouattara, a former prime minister.
Gbagbo and Ouattara have both sworn themselves in as president of the west African state and each has named a separate prime minister.
The ex-rebel chief named as prime minister in Ouattara's rival government, Guillaume Soro, pressed ahead with his first cabinet meeting Monday and warned Gbagbo he could face an armed revolt if he does not back down.
Supporters of Ouattara hit the streets in parts of the main city Abidjan on Monday as in the two previous days, burning tyres and raising barricades before police dispersed them with tear gas, AFP correspondents reported.
Soro meanwhile gathered the members of his new government "to tackle some current issues and decree certain action to be taken by each of the ministers," their spokesman Patrick Achi told reporters.
Gbagbo, 65, has defied international calls to end his 10 years in power after the United Nations recognised Ouattara as the winner of a presidential vote which was supposed to ensure peace but instead has been marred by deadly violence.
Focus: Tough balancing act for African Union in Ivory Coast
Soro, who has been reappointed as prime minister by Ouattara and has several thousand northern rebel troops behind him, warned Gbagbo on Monday they could take up arms if he tries to cling on. Gbagbo has nominal control of the national army.
Asked whether he would be ready to reactivate his forces to "unseat" Gbagbo, Soro told France's Europe 1 radio: "If he pushes us to it, we'll have no other choice," but insisted he was seeking a peaceful "transition of power."
A spokeswoman for EU chief diplomat Catherine Ashton said Monday the bloc may consider targeted sanctions "against those who obstruct the peaceful transition and the election" if the crisis is not resolved quickly.
Mbeki was dispatched urgently Sunday by the 53-member African Union (AU) and met with both rivals, who raised the stakes, Ouattara's side forming a new government and Gbagbo naming his own prime minister, Gilbert Marie N'gbo Ake.
"The African Union is very, very keen indeed that the peace in Cote d'Ivoire should be maintained," Mbeki told reporters after a second meeting with Gbagbo on Monday.
"We indeed hope that the leadership of this country will do everything it can to make sure that peace is maintained," before leaving without any further declaration.
Hundreds of people fearing fighting have crossed from western Ivory Coast into neighbouring Liberia, an official there said.
On Monday UN spokesman Haq told AFP that "given the security situation" in Ivory Coast about 460 non-essential staff there will be relocated to the Gambia.
At least 17 people have been killed in election-related clashes in Ivory Coast in the past two weeks and there have been unconfirmed reports of other violence around the country, the world's biggest cocoa producer.
Ivory Coast was split in two between north and south by a civil war in 2002 and 2003. The election was supposed to end a decade of conflict in the country, which was once the most prosperous in west Africa.
"It could take several months but if there is still no political solution we cannot rule out a real risk of a return to an armed conflict," said Gilles Yabi, a senior regional analyst at the International Crisis Group.