United Nations Secretary-General Ban Ki-moon said Tuesday that civil war is possible in the Ivory Coast after presidential elections last month left both candidates claiming victory.

Incumbent candidate Laurent Gbagbo refuses to accept his opponent, Alassane Ouattara, won even after the U.N. recognized Ouattara as the winner.

U.N. officials say Gbagbo supporters are threatening the organization's peacekeepers.

"Facing this direct and unacceptable challenge to the legitimacy of the United Nations, the world community cannot stand by," said Ki-moon.

Since the election, Ouattara has been protected by the U.N. at the Golf Hotel in Abidjan.

But in a surprise move, Gbagbo, in a television address, proposed an international panel to examine the election results. He also said Ouattara could leave the hotel.

The African country has long had civil unrest between the government-held south and Muslim rebels in the north.

Read more about the possible civil war here.