Before United Nations (UN) peacekeepers hurriedly abandoned their base in Kidal in northern Mali on Tuesday, they made a costly call: with insurgents stationed nearby, they destroyed sensitive equipment to avoid it falling into the wrong hands, the UN said.

Shortly after the last UN convoy rolled out, the ethnic Tuareg rebels announced they had taken over the base. Photos posted on social media on Wednesday appeared to show locals loading trucks with looted goods, including tyres, cables and chairs.

Mali's ruling military junta in June ordered the decade-old UN mission, known as MINUSMA, to leave as its relations soured with former international allies. MINUSMA has accelerated its departure in recent weeks as northern Mali has been engulfed in fighting between the rebels and government forces vying for control over areas it vacates.

Chaos has ensued.

Bloody confrontations have surrounded at least two UN bases, and two have also been looted, according to two sources with direct knowledge of the withdrawal. At least a dozen peacekeepers have been injured by explosive devices hit by UN convoys heading south, according to UN statements.

The UN has acknowledged difficulties with its departure. MINUSMA said in statements that it has been forced to destroy equipment including vehicles, ammunition and generators that its forces couldn't evacuate after the government imposed restrictions on moving them. Mission spokesperson Fatoumata Sinkoun Kaba told Reuters that millions of dollars of kit has been lost.

Authorities have denied approval for air support for convoys travelling over some of the most volatile terrain in West Africa. They ordered a halt to some imports of fuel and spare parts, and in some cases jeopardised the safety of departing peacekeepers, according to the two sources with direct knowledge of the withdrawal.

Mali's government did not respond to requests for comment for this story.

Security analysts have warned that the Malian state could collapse altogether, further destabilising a region where insurgents with links to al Qaeda and Islamic State are gaining ground.

MINUSMA had originally planned to leave Kidal in mid-November, the sources said. The equipment that was destroyed there and at two other northern bases could have been removed by UN trucks earlier, but Mali's junta blocked access, the UN said.

Four aircraft have been grounded for lack of parts, the UN told Reuters, without specifying what kind of aircraft.

Dozens of UN import requests have gone unanswered, the UN Department of Peace Operations and the Department of Operational Support said in an internal letter to the Security Council on October 14, seen by Reuters.

With routes to the south under threat from Islamist militants, the mission has explored the possibility of exiting through Algeria to the north or Mauritania to the west, the letter said, both of which were proving "difficult to operationalise".

The two sources, who asked to remain anonymous to speak on a sensitive topic, said they believe Mali's junta has sought to delay the retreat to give it time to reach the bases before the UN leaves.

Reuters was unable to confirm this but the junta has expressed concern in public pronouncements about the UN leaving bases before it arrives, including after the Kidal departure. Last month, it called the acceleration of MINUSMA's withdrawal a "betrayal".

"NASTY WAR"

The situation marks a bitter end to the UN's mission in Mali, where it deployed after the north was overrun by Islamist militants and Tuareg rebels in a 2012 uprising. MINUSMA initially helped restore some calm, but violence has persisted.

Thousands of civilians have died, and more than 170 peacekeepers have been killed in combat, making MINUSMA the UN's deadliest mission.

Worsening insecurity prompted military coups in 2020 and 2021. The junta then kicked out French troops who were helping fight the Islamists, teamed up with Russian private military contractor the Wagner Group, and ordered MINUSMA to leave.

The mission has until December 31 to pack up. So far, more than 6 000 of nearly 14 000 personnel have left, the UN spokeswoman said.

The Tuareg rebels signed a 2015 peace agreement brokered by MINUSMA but maintained control of much of the north from Kidal. That accord has fallen apart since the mission began moving out.

The first sign of trouble came in early August, when fighting broke out between Mali's army and Tuareg rebels around the UN's camp in Ber in the north. The mission left the camp on August 13, two days early. Its convoy was attacked twice that day, injuring four peacekeepers, it said.

In October, gunfire around its base in Tessalit, near the Algerian border, forced peacekeepers to shelter in bunkers, the UN said. On October 19, shots hit a MINUSMA plane landing at the airstrip.

When the last troops left Tessalit on October 21, they were denied air support for the nine-day journey across the unpoliced desert.

"They are effectively endangering the lives of our troops," one of the sources said. As in Kidal, peacekeepers destroyed equipment before leaving that could have been transported in trucks earlier, if the government had allowed.

Air support was also denied convoys departing Kidal on a 350-kilometre (217-mile) journey south to the city of Gao, the MINUSMA spokesperson said.

Three security analysts told Reuters that Kidal, a Tuareg stronghold from which rebels have long fought for autonomy of the desert region they call Azawad, was a potential flash point now that the UN has left. It is not clear how well positioned the Malian army is to take back the base. It has been trying to reach the city in recent weeks, but progress is slow, the analysts said.

"If the base in Kidal falls into the rebels' hands, this will cause an outcry in Bamako," said Yvan Guichaoua, senior lecturer at the University of Kent's Brussels School of International Studies. "A nasty war may eventually erupt."