Ivory Coast's main city is quiet but tense, as fears loom that a political power struggle will spark more deadly clashes.
Armed forces loyal to incumbent president Laurent Gbagbo are patrolling Abidjan, where the streets are otherwise deserted and businesses closed.
Mr. Gbagbo is refusing to cede power to Alassane Ouattara, the internationally recognized winner of last month's presidential election.
Mr. Ouattara called on his supporters to march through Abidjan Friday for a second attempt to seize a state broadcaster's building.
During a failed attempt to take the building Thursday, clashes between Mr. Ouattara's supporters and armed forces killed at least 20 people.
International pressure on Mr. Gbagbo mounted on Friday, when French President Nicolas Sarkozy warned him to give up power by the end of this week or face EU sanctions.
Kenyan Prime Minister Raila Odinga said the African Union must be ready to use military force to remove Mr. Gbagbo and preserve democracy.
Meanwhile, the U.N. Refugee Agency said Friday that more than 4,200 Ivorians have fled to Liberia because of fears the political crisis will lead to violence.
The United States has also issued a new travel warning for Ivory Coast, urging citizens to avoid traveling there. The State Department has authorized non emergency personnel and some family members of embassy workers to leave the country.
Mr. Gbagbo has ruled the country since 2000. His term officially ended in 2005, but he has remained in office through repeated election delays.