Militants from Al-Qaida in the Islamic Maghreb (AQIM) decapitated a Malian this week that they accused of aiding France's anti-jihadist operation in the region, security sources said Saturday.

"A Malian civilian accused of collaborating with French forces in the Barkhane operation was executed and decapitated by AQIM this week," a military source with the United Nations' MINUSMA mission in Mali said of Thursday's killing in the marketplace in Tichift, 120 kilometers (75 miles) north of Timbuktu.

Special agents are holding three people suspected of helping armed jihadists launch an attack on a nightclub in Mali's capital in which five people died, government sources said Thursday.

The arrests came 12 days after assailants with grenades and automatic rifles struck La Terrasse, a favored nightspot among Westerners in Bamako, killing three Malians, a Frenchman and a Belgian.

Mali's Tuareg-led rebels described a proposed peace deal with the government as "fundamentally flawed" in a statement sent to Agence France-Presse on Monday summarizing days of their discussions on the accord.

The Algiers Agreement, hammered out over eight months of tough negotiations in Algeria, was proposed in order to bring a lasting peace and transfer significant powers to an area of northern desert the size of Texas that the rebels refer to as "Azawad".

Concerns are rising that a deadly jihadist attack on a popular nightclub in Mali's capital may foreshadow moves by extremist groups that have been routed in the desert to sneak operatives into towns to mount strikes.

Responsibility for the March 7 nightclub attack in Bamako by a heavily-armed gunmen that left three Malians, one French national and a Belgian dead was claimed by al-Murabitoun, a jihadist group run by Algerian militant Mokhtar Belmokhtar, whose fighters were pushed from northern Mali into the barren Sahel by the French-led military intervention launched in 2013.

Malian special forces killed a suspect Friday in last week's deadly jihadist attack on a nightclub in the capital, officials said, dramatically igniting a probe which had shown little progress.

Bamako has been on high alert since a heavily armed gunman burst into La Terrasse, a popular venue among expatriates, on Saturday and killed five people, including a French national, a Belgian and three locals.

Mali's Tuareg-led rebels met Wednesday in the northeast of the country to decide whether to sign a peace deal already accepted by the government and smaller armed groups, a participant told Agence France-Presse.

Between 150 and 200 mainly Tuareg figures traveled from across the region to the city of Kidal to take part in the talks, expected to last several days, said the source, speaking on condition of anonymity.

Mali vowed Monday not to bow to terror and to punish the jihadists behind a deadly nightclub attack in the capital, as local and French investigators joined forces to hunt down the killers.

Bamako has been on high alert since a heavily-armed gunman burst into La Terrasse, a popular venue among expatriates, early Saturday and killed five people, including a French national and a Belgian.

Two civilians and a U.N. peacekeeper were killed on Sunday as militants attacked a barracks used by the United Nations' MINUSMA force in northern Mali, it said in a statement.

"This morning around 5:40am (0540 GMT), the MINUSMA camp in Kidal suffered more than 30 rockets and shells during a complex attack," the force said in a statement.

Police in Mali Sunday hunted for the killers of two Europeans and three Malians in a jihadist attack on a nightclub, as a deadly assault on a U.N. barracks in the north heightened security concerns.

Officers in bulletproof vests patrolled the streets of the capital Bamako, where a masked gunman had burst into La Terrase, a popular venue among expats, spraying automatic gunfire and throwing grenades early Saturday.

U.N. chief Ban Ki-moon on Friday urged Mali's Tuareg rebel groups to sign a peace deal agreed nearly a week ago in Algeria.

The Malian government signed the agreement over the weekend, along with some northern armed groups, but the main Tuareg rebel alliance, known as the Coordination, asked for more time.