The most powerful of the Central African Republic's armed groups said in a statement on Monday it will quit a rebel coalition aiming to unseat President Faustin Archange Touadera.
The Unity for Peace in Central Africa (UPC), mainly active in the country's east, "commits to withdraw from the Coalition of Patriots for Change" (CPC), the group's head Ali Darassa wrote.
The coalition is an alliance of some of the war-torn country's most powerful armed groups, who joined together on December 19 accusing Touadera, the frontrunner in the December 27 elections, of trying to fix the vote.
Its components were drawn from militia groups that, together, controlled two-thirds of the impoverished country.
Touadera was reelected with barely one in three voters able to cast their ballot because rebel groups control most of a country.
Darassa said Monday that since the "electoral crisis the population has suffered terribly from insecurity, the health situation, famine and the lack of humanitarian assistance".
The UPC, the statement continued, "reiterates its commitment to the Khartoum Accord process", a peace agreement signed in February 2019 between the government and 14 armed groups.
Tensions have been high in the Central African Republic since the December election, although the surge in violence in recent months is just the latest flare-up in a civil war that has lasted eight years.
More than 30,000 people have fled the country due to the violence surrounding the elections, the UN says, while tens of thousands more have been internally displaced.
On January 13, rebels launched twin attacks on the outskirts of the capital -- the first time they had struck so close to the city since the start of their offensive.
But their offensive foundered faced with government forces backed by 12,000 UN peacekeepers force, Russian paramilitaries and Rwandan troops.
Since January, the government and its allies have recaptured towns once held by fighters from the alliance of militias.
Bangui has accused former president Francois Bozize, the head of the CPC, of attempting a coup.
Mineral-rich but rated the world's second-poorest country on the Human Development Index, the CAR has been chronically unstable since independence 60 years ago.