Amnesty International said Wednesday that armed Tuaregs and Islamists, who seized northern Mali after a coup, had carried out grave rights abuses such as rape, murder and using child soldiers.

A report released by the London-based rights group said soldiers had also carried out extrajudicial killings, branding the crisis Mali's worst human rights situation in 50 years.

Two West African envoys quit Mali Saturday after failing to reach agreement with coup leaders on naming the head of a transitional government.

Ivory Coast envoy Adama Bictogo said prior to departure that talks with the ex-junta, who staged a coup on March 22, concerning the post of interim leader had failed.

Members of al-Qaida in the Islamic Maghreb have desecrated a saint's tomb in the fabled city of Timbuktu, an official said on Saturday.

"Members of AQIM, supported by (the armed Islamist group) Ansar Dine, have destroyed the tomb of Saint Sidi (Mahmoud Ben) Amar. They set fire to the tomb," the official told Agence France Presse on condition of anonymity, adding that they had pledged to destroy others too.

An offshoot of al-Qaida now dominates northern Mali, which fell into rebel hands in March, regional security sources said Saturday as authorities struggled to assert control in the capital Bamako.

"Today it is al-Qaida in the Islamic Maghreb which occupies a dominant position in the three areas of northern Mali thanks to its alliance with the Islamic Ansar Dine group and the influx of Tunisian, Libyan and Moroccan fighters," a Mauritanian source told Agence France Presse.

The soldiers who staged a putsch in Mali five weeks ago said early Tuesday they had defeated an overnight counter-coup by forces loyal to ousted president Amadou Toumani Toure.

Gunfire had erupted at the national TV and radio station, the airport and at the garrison town near the capital Bamako that is the headquarters of the rebel soldiers led by Captain Amadou Haya Sanogo.

The captain who led a coup in Mali last month before handing power back to a civilian president rejected Saturday the decision by West African states to send troops.

"All the decisions announced in Abidjan were reached without consulting us," Amadou Haya Sanogo told reporters. "I do not agree with the deployment of soldiers from the Economic Community of West Africa States", or ECOWAS.

Mali's interim prime minister Cheick Modibo Diarra on Wednesday formed a government of 24 members, including three representatives of the military.

The three will hold the defense, interior and civil protection portfolios in the west African country where the military seized power in a coup last month before relinquishing control under a deal brokered by west African bloc ECOWAS, said an official speaking on condition of anonymity.

Special forces from Burkina Faso swept into rebel-held northern Mali on Tuesday aboard a helicopter and whisked a Swiss hostage to safety in a pre-arranged handover by Islamist rebels.

Beatrice Stockly, her face clear of the black turban the rebels had her wear, appeared tired but in high spirits on the helicopter flying her to Ouagadougou after the rebel group Ansar Dine handed her over in Timbuktu.

The African Union's peace and security body met Tuesday to discuss ongoing political crises in Mali and Guinea-Bissau and the escalating conflict between Sudan and South Sudan, urging immediate end to the conflicts.

"It is important... to find fast, equitable, just and durable solutions to the conflict in Guinea-Bissau and in Mali," AU security commissioner Ramtane Lamamra said at the meeting's opening.

The Malian Red Cross said Saturday it was able to transport five tons of supplies and medicine to Timbuktu, in the grip of a humanitarian crisis after being seized by rebels.

"We took five tons of supplies and rice, to the Timbuktu hospital, mats, blankets, but also medicine," Red Cross president Adam Diarra told Agence France Presse after leaving the fabled city where the team arrived on Thursday.