Top members of the rebel coalition loyal to the Central African Republic's former president have left the capital Bangui, witnesses said, as eight people were reported killed in mob violence.
The convoy carrying members of the mostly Muslim Seleka coalition was guarded by Chadian peacekeepers, Human Rights Watch emergencies director Peter Bouckaert said on Sunday.
"In the middle of the convoy, I saw several Seleka generals, including the head of military intelligence," Bouckaert said.
"It feels a bit like the endgame for Seleka in Bangui."
It was not immediately clear why they were leaving the capital or where they were heading. Many Seleka fighters, a large number of whom came from neighbouring Chad and Sudan, have abandoned the capital in recent months following the deployment of French troops.
Chadian peacekeepers have been accused of supporting Seleka throughout the conflict, which began when the Seleka rebels seized power in the majority Christian country in March.
Also on Sunday, the Red Cross said eight people were killed and seven others injured by a mob in Bangui.
"We even had one woman whose throat was slit," Antoine Mbao Bogo, president of the country's Red Cross, told Reuters news agency.
The deaths come as US Secretary of State John Kerry warned that Washington was prepared to impose sanctions against those responsible for sectarian violence in the country.
"The United States is prepared to consider targeted sanctions against those who further destabilise the situation, or pursue their own selfish ends by abetting or encouraging the violence," Kerry said in a statement.
The United Nations estimates that more than 2,000 people have been killed since March in tit-for-tat bloodshed that a French intervention force and thousands of African peacekeepers have failed to stop.
Christian self-defence groups, known as "anti-balaka", or anti-machete, have taken up arms against the rebels.
Almost one million people, or a quarter of the population, have been displaced by fighting.
In a statement issued on Sunday, Amnesty International warned that both Christian and Muslim civilians in parts of northwest CAR were "in imminent danger of attack" because of a heavy militia presence and the absence of peacekeepers.
"More deaths are very likely but this could be prevented by even a small presence of international peacekeepers," Amnesty senior crisis adviser Donatella Rovera said.