As General Bozize is a northerner, like Mr Patasse, he could split the president's support.

BBC: General Francois Bozize

Mr Bozize seized power in March 2003 while the then President Ange-Felix Patasse was out of the country.

BBC: Francois Bozize casts his vote in the May poll

There have been reports of serious violence and looting in the northern suburbs by Congolese fighters supporting President Ange-Felix Patasse.

BBC: Chadians attacked in Bangui

The army, backed by the MLC and Libyan troops, launched its offensive on Wednesday - six days after fighting began between the insurgents supporting General Bozize and troops loyal to President Patasse.

BBC: Chadians attacked in Bangui

The Gbaya in the east and Banda in the west control the largest land mass, although since independence in 1960 until Patasse gained power, the country been controlled by the southern Oubanguiens and Ngbandi.

BBC: UN steps into CAR ethnic tension