(CNN) -- The U.S. Embassy in Bangui has shut down operations and its personnel have left the Central African Republic amid lingering unrest between the government and rebels.
The U.S. State Department said that its ambassador and diplomatic team left the capital, but that the United States is not cutting off diplomatic relations with the Central African Republic.
"This decision is solely due to concerns about the security of our personnel and has no relation to our continuing and long-standing diplomatic relations with the CAR," the State Department said in a statement Thursday.
The United Nations had also begun to relocate personnel.
Bangui appeared calm Friday, a day after throngs of protesters took to the streets to demand foreign intervention amid indications that rebels might advance on the city.
National radio reported some protests, but an eyewitness said protesters appeared to have gone indoors.
"The situation here today is calm. There is no one on the streets," said Margaret Vogt, a special representative of the U.N. secretary-general. "Yesterday around this time, there were about thousand people marching and singing."
President Francois Bozize asked for help from other nations to stave off rebel advances that threaten his rule.
Bozize asked France and the United States on Thursday to help ensure "the rebels return home ... instead of destroying and killing Central Africans."
Attacks on several cities by the coalition of rebel groups known as Seleka undermine peace agreements in the Central African Republic. Rebels say they are fighting because the government has broken its promises.
The rebels were about 190 miles from Bangui. No new attacks had been reported since Wednesday, diplomatic adviser Honore Nzessiwe said Thursday.
The Central African Republic government is seeking negotiations with the rebels in Libreville, Gabon, he said. In the meantime, troops from the Central African Multinational Forces were expected to arrive to bolster security in the capital, he said.
The lull in rebel attacks may be evidence that they are respecting a promise to stop their advance, Vogt said.
U.N. efforts have focused on calling for a disarmament process, but a lack of funding from the European Union meant that such a program could not be carried out in the country's northeast, where there is fighting, she said.
Bozize directed his call for help to France, saying "the French are our cousins. They should fix what is happening."
France has a permanent presence of 200 to 300 military personnel at Bangui's airport under the mandate of the Economic Community of Central African States.
But French President Francois Hollande said Thursday that the troops are not intended to "protect a regime" against the advance of the rebels, but instead French nationals and interests.
France will not "interfere in the internal affairs of a country, in this case, CAR," Hollande said, adding: "That time is over."
Asked about a possible intervention in favor of displaced people or refugees, the French president said that his country could not "intervene unless there is a U.N. mandate," and, he said, "this is not the case."
"But in general, we are always for civilians to be protected and preserved, and we will do our duty again," he said.
The Central African Republic came into being after the French colony known as Ubangi-Shari gained independence in 1960.
CNN's Bharati Naik, Stephanie Halasz and Saskya Vandoorne contributed to this report.