The armed groups decided “to combine all of our movements into a single entity, called the Coalition of Patriots for Change or CPC, under a unified command”, they wrote in the statement.
The CPC invited “all other armed groups to join”. They also urged its members to “scrupulously respect the integrity of the civilian population” and to allow vehicles belonging to the United Nations and to humanitarian groups to circulate freely.
The UN mission in the CAR, MINUSCA, said on Friday that its blue helmet forces were on “maximum alert” to prevent armed groups from disrupting the elections.
The CAR spiralled into conflict in 2013, when then-president Francois Bozize was overthrown by the Seleka, a rebel coalition drawn largely from the Muslim minority.
The coup triggered a bloodbath between the Seleka and so-called “Anti-balaka” self-defence forces.
France intervened militarily in its former colony and after a transitional period, elections were staged in 2016 and won by president Faustin-Archange Touadera.
Inter-communal fighting has receded in intensity in the last two years, but armed groups hold sway over two-thirds of the country, often fighting over resources.