One of the main armed Islamist groups in northern Mali claimed responsibility Friday for a suicide bombing and armed assault on Timbuktu which left one soldier and 12 militants dead.

The al-Qaida-linked Movement for Oneness and Jihad in West Africa (MUJAO) said Thursday's attacks on the desert city it had controlled for seven months before being ousted had "opened a new front" in the conflict with Malian troops.

France on Thursday appointed a new ambassador to Mali, the foreign ministry said, amid a French-backed military intervention against Islamist rebels in the west African nation.

Gilles Huberson will replace Christian Rouyer, foreign ministry spokesman Philippe Lalliot said, adding that it was in the framework of a routine reshuffle of French diplomatic posts in Africa.

A Malian soldier died in Timbuktu's first suicide bombing as the city came under assault Wednesday night, after French President Francois Hollande vowed a military operation to drive out radical Islamists from Mali was in its last phase.

The bomb went off as a group of armed men, trying to force their way into the ancient city, exchanged fire with French and Malian soldiers who chased out the Islamists in late January.

French troops will begin pulling out of troubled Mali "from the end of April", French Prime Minister Jean-Marc Ayrault told parliament on Wednesday.

Ayrault said a meeting next Monday between lawmakers in France's National Assembly and Senate would assess the involvement of French troops to help flush out Islamist rebels in the west African country "even if our troops will begin coming home from the end of April".

A French hostage has been executed in Mali, a man claiming to be a spokesman for al-Qaida in North Africa told Mauritania's ANI news agency late Tuesday.

A French foreign office spokesman said Paris was trying to verify the report of the killing of Philippe Verdon, who was kidnapped in November 2011, adding that "we don't know at the moment" whether it was reliable.

Fifteen Islamist fighters have been killed in recent days in the northern Mali region of Gao, the French army said Tuesday, announcing the seizure of a large cache of arms and ammunition.

The claim came two weeks after France said more than 150 Islamist rebels had been killed since the middle of February in Mali. French losses in the intervention have been limited to five casualties.

A French jihadist arrested earlier this month in Mali returned to France on Tuesday and was immediately detained, judicial and informed sources said Tuesday.

The 37-year-old is among six men captured at the start of this month during fighting between French-led troops and Islamist rebels in the Ifoghas mountains in northern Mali.

A French corporal was killed during fighting in northern Mali, bringing to five the number of French deaths since the January 11 intervention to oust armed Islamist groups, President Francois Hollande's office said Sunday.

The statement did not elaborate on the circumstances of the soldier's death and paid tribute to the French forces involved in "the final and most difficult phase of their mission" in Mali.

Thousands of people who fled when Islamists attacked the largest city in Mali's war-torn north have returned, a survey by a local charity working to resettle refugees told Agence France Presse on Thursday.

Tassaght said a study of returning refugees and internally displaced people indicated that 5,800 residents who fled the occupation by al-Qaida-linked Islamists had come home, most after Gao was liberated in late January.

Mali's interim president defended the country's rights record Tuesday against accusations by the United Nations that the military was guilty of atrocities against ethnic groups in the war-torn north.

Dioncounda Traore, on a visit to the neighboring west African state of Senegal, said reprisals highlighted by a U.N. mission to Mali were rare but vowed that those found guilty of abuses would be hunted down and prosecuted.