Mali's interim president Dioncounda Traore has formed a national unity government in an attempt to bring stability to a country split in two after Islamists seized northern regions following a coup.

The west African nation has been in crisis since March when democratically elected president Amadou Toumani Toure was overthrown by the military, who two weeks later handed over power to a transitional administration.

The ensuing political turmoil allowed Al-Qaeda-linked Islamist rebels to wrest control of the northern desert regions.

The national unity government announced by presidential decree on Monday has 31 ministers of almost all political shades including four women.

Tieman Coulibaly, a member of the anti-coup Front for Democracy and the Republic (FDR) party, becomes foreign minister under controversial Prime Minister Cheick Modibo Diarra.

The new administration also includes a new ministry of religious affairs, headed by Yacouba Traore.

Among those reappointed are three military members seen as close to the former junta: Defence Minister Colonel Yamoussa Camara, Security Minister General Tiefing Konate and Minister for Territorial Administration Colonel Moussa Sinko Coulibaly.

Justice Minister Malick Coulibaly and Health Minister Soumana Makadji were also reappointed.

The Economic Community of West African States (ECOWAS), which has proposed sending an intervention force to Mali to help the weak transitional government, ordered Bamako to form a government of national unity by July 31 that would be able to reconquer the north.

The ultimatum was later extended. ECOWAS also warned Bamako it could be expelled from the group.

With the country split in two, political parties including Traore's had called for Diarra's ouster.

But on August 13 Traore ‘renewed his confidence’ in Diarra and asked him to make proposals on forming a government of national unity, after consultations by Traore with the country's ‘civil society’ including political parties and the junta.

The communication ministry will be taken over by Bruno Maiga, a junior minister in the previous administration formed on April 24.

Coulibaly replaces Sadio Lamine Sow, seen as close to Burkina Faso's President Blaise Compaore, the top West African mediator in Mali's crisis.

Diarra, an internationally renowned astrophysicist who came to power on April 24, has been under fire from much of Mali's political class including Traore's party who accused him of incompetence and called for his departure.

They claimed he had no ‘strategy’ no solve the problem in the vast north of the country where Islamist groups seized key cities in the chaos following the March coup.

The takeover was spearheaded by Tuareg rebels seeking an independent state for their nomadic desert tribe, but the extremists have pushed them aside and seek an Islamic state in the zone, an area larger than France or Texas.

The groups - which security experts say are acting under the aegis of Al-Qaeda in the Islamic Maghreb (AQIM) - have since imposed strict Islamic law in northern Mali, prompting outrage as they stoned an unmarried couple to death and cut off the hand of a thief.

Fighters from Ansar Dine also destroyed part of Timbuktu's cultural treasures, declaring the ancient Muslim shrines ‘haram’ or forbidden in Islam shortly after UNESCO placed them on a list of endangered World Heritage sites.