The three main rebel groups in northern Mali have agreed to merge, creating a united front in an ongoing peace process with the government.

A Tuareg uprising in northern Mali last year plunged the country into chaos, leading to a coup in the capital Bamako and the occupation of the north by rebels.

Since a French-led invasion in January to drive out the fighters, rebel groups have been scattered and reconciliation with them is one of the greatest challenges for President Ibrahim Boubacar Keita.

The three groups that merged on Monday were the National Movement for the Liberation of Azawad (MNLA), the High Council for the Unity of Azawad (HCUA) and the Arab Movement of Azawad (MAA). 

The merger will take effect in 45 days, they said.

As part of a peace deal signed with the government in Burkina Faso in June, the three groups said they would disarm.

Still, the region remains unstable and last week two French radio journalists were killed by unidentified fighters. The secretary general of MNLA, Bilal Ag Acherif, said his group would cooperate with authorities to find the perpetrators.

On Monday, four people were killed in northern Mali after their truck ran over a landmine, according to officials, the latest sign of insecurity in the country.

The unrest comes as UN chief Ban Ki-moon touched down in Mali late on Monday to begin a regional tour to highlight the battle against poverty.

Ban, World Bank President Jim Yong Kim and top officials from the African Union, African Development Bank and European Union will spend Tuesday in Mali before travelling to Niger, Burkina Faso and Chad.

Mali has produced four rebellions since independence from France in 1960. Its light-skinned Tuareg people say successive black African governments in the capital have excluded them from power.

Source: Agencies