More than 6,000 people have fled Cote d'Ivoire into two neighboring countries of Liberia and Guinea, the UN refugee agency (UNHCR) has said.

Cote d'Ivoire has been plunged into political uncertainty after incumbent President Laurent Gbagbo refused to concede electoral defeat to Alassane Ouattara.

The agency said in a statement reaching Xinhua on Wednesday that some 6,000 Ivorians have fled into eastern Liberia, while another 200 have arrived in Guinea.

It was boosting its contingency plans for Cote d'Ivoire and had airlifted additional relief supplies to Liberia and Guinea from its emergency stockpiles in Copenhagen, the UN agency said.

The statement quoted UNHCR spokesperson Adrian Edwards as saying that most of the Ivorian refugees seeking protective shelter in Liberia and Guinea were women and children.

The agency has deployed additional staff to Liberia's Nimba County, which is hosting most of the refugees, the spokesperson said.

Edwards said the deployment was to ensure greater border monitoring, proper registration of the incoming refugees and distribution of relief items.

The UN had endorsed the victory of opposition leader and President-elect, Ouattara, in the November 28 run-off presidential elections which Gbagbo claim to have won.

There have been alleged clashes between demonstrators and Gbagbo's military forces.

The UN estimates that at least 50 people have been killed from the clashes, 200 injured, 470 arbitrarily arrested and detained and many disappearances.

On Monday, the UN Security Council extended the mandate of its peacekeeping mission in Cote d'Ivoire, initially due to expire on December 31, to June 30, 2011.

The Council rejected Gbagbo's presidential order for UN and foreign troops to leave the country.

The UN has more than 10,000 troops in the country.

Meanwhile, the Economic Community of West African States (ECOWAS) announced on Tuesday that it would hold an emergency summit on the situation in Cote d'Ivoire on Friday.

The regional body said in a statement reaching Xinhua that the Heads of State and Government will be discussing the developments in Cote d'Ivoire.

The ECOWAS Commission said it has learnt with surprise and disappointment, the ultimatum issued by the outgoing President of Cote d'Ivoire, Gbagbo, to UNOCI, the UN Peacekeeping Mission, and the French Forces, Licorne, to leave the country immediately.

"ECOWAS wishes to state that the ultimatum, far from helping the situation, would further heighten tensions and worsen the plight of the vulnerable in the country," the body said.

"The Commission calls on the outgoing President to desist from his stand-off with the peacekeeping forces but rather to join in the effort in seeking ways of creating an environment of peace and security in the country," it added.

"It will like to recall the Decision of December 7, 2010 by the ECOWAS Authority recognizing Alassane Ouattara as the legitimate winner of the presidential run-off election of November 28, 2010 and urges Laurent Gbagbo to yield power with dignity without further delay," the commission said.

The Commission urges Gbagbo to reconsider his confrontational stance towards the international community and act in the supreme interests of the country and the region by ensuring a smooth transfer of power, it added.

The Commission had on December7 suspended Cote d'Ivoire from the regional bloc over the country's electoral dispute on Tuesday and recognized Alassane Ouattara as the winner of Cote d'Ivoire's presidential run-off.

Nigerian President Goodluck Jonathan, who is also chairman of the 15-member regional bloc, made the decision after having an emergency meeting in Abuja with leaders from Burkina Faso, Liberia, Ghana, Senegal and Togo.

Jonathan ruled out the possibility of a unity government involving both Gbagbo and Ouattara as a way to settle the impasse.

In the presidential run-off on November 28, incumbent President Gbagbo and former prime minister and opposition leader Ouattara competed for the top office of the country.

Ouattara was declared winner of the election by the electoral commission while the Constitutional Council, which has the final say on the results of the poll, said Gbagbo won the vote.

Gbagbo was sworn in as the new president of the west African country by the Constitutional Council, and Ouattara also swore himself in as the president.