The U.N. peacekeeping mission in Mali has deployed 8,280 soldiers on the ground, 74 percent of the number mandated a year ago, and still lacks utility helicopters, a new report says.

The U.N. peacekeeping force in Mali, known as MINUSMA, took over in July 2013 from African forces fighting armed groups linked to al-Qaida that occupied northern Mali in 2012.

A suicide bomber killed at least four Malian and Chadian soldiers at a military camp in rebel-infested north-eastern Mali on Wednesday, army sources told Agence France Presse.

The bomber struck in a car laden with explosives at the entrance to the camp, which houses Mali soldiers as well as international troops from the United Nations' MINUSMA peacekeeping force, they said.

A Malian army officer has been arrested for "an attempted coup," a senior government official said on Friday, a day after his family reported he had been kidnapped.

"Lieutenant Mohamed Ouattara has been arrested -- and not abducted -- for an attempted coup, for a bid to destabilize the institutions of the republic and for a breach of state security," the official said, asking not to be named.

Men in army uniform overnight abducted an army officer who was opposed to a successful military coup in Mali two years ago, his family said Thursday.

"This was a trap laid for my son, Lieutenant Mohamed Ouattara," retired colonel Yaya Ouattara told AFP. "He was kidnapped during the night... by armed individuals wearing military uniform."

Frenchman Serge Lazarevic, kidnapped in Mali by al-Qaida in 2011, appeared in a video aired on Tuesday by Dubai-based Alaan television urging French President Francois Holland to act to secure his release.

Lazarevic, wearing a black turban, sporting a long beard and flanked by armed men, said the video was being recorded on May 13.

Mali's Defense Minister Soumeylou Boubeye Maiga resigned Tuesday, a week after government troops were defeated by armed rebels in the restive northeastern town of Kidal, a presidential spokesman said.

"Mali's defence minister has offered his resignation and it has been accepted," the spokesman told Agence France Presse.

An Algerian general on Monday warned of a "worrying" situation on the country's vulnerable borders, faced with chaos in neighboring Libya and northern Mali.

"The deteriorating security situation in the neighboring countries are all factors that require permanent vigilance and rigorous deployment," Boualem Madi told Algerian radio.

Malian Defense Minister Soumeylou Boubeye Maiga said Sunday around 50 soldiers had been killed during recent fighting with armed rebels in the northern desert town of Kidal.

"We have about 50 killed, unfortunately, and 48 injured. We don't know the toll of the other side but we know they also suffered losses," Maiga told the public broadcaster ORTM. 

The Mali government signed a ceasefire deal with three rebel groups in the northern desert Friday, the African Union's negotiator announced, after the Tuareg and Arab insurgents captured the flashpoint town of Kidal.

The town is the cradle of Mali's separatist movement, which wants independence for a vast swathe of northern desert it calls "Azawad" and which has launched several rebellions since the 1960s.

The head of the African Union launched talks Friday with Tuareg rebels who humiliated Mali's army in an offensive in the northern desert, as the U.N. warned of growing numbers fleeing the fighting.

Around 20 Malian soldiers have been killed and 30 wounded since Wednesday as insurgents captured the flashpoint northern town of Kidal and the smaller settlement of Menaka, according to the defense ministry.