Mali's army drove closer on Saturday to the town of Kidal clashing with Tuareg separatist and rebel groups in what could signal the start of fighting for the strategically important northern crossroads.
Since seizing power in a coup in 2020 the African country's military rulers have made a priority of re-establishing sovereignty over all regions and Kidal could become a key battleground.
Military, political and rebel sources all reported the clashes.
But details such as a casualty toll or tactics involved could not be confirmed independently in the remote region.
The rebels in Kidal cut telephone links on Friday in anticipation of an army offensive following several days of airstrikes.
The Permanent Strategic Framework (CSP), an alliance of predominantly Tuareg armed groups said it had been involved in "vigorous combat" against a convoy of army soldiers and mercenaries from Russia's Wagner group.
The CSP post on social media said "considerable losses" had been inflicted on the convoy which had retreated.
However, the army said on social media networks that it had "broken the defensive line" set up by the rebels near Kidal, and assured that it was continuing its advance, which "will be carried out successfully".
Earlier, an army officer told AFP: "We are a few dozen kilometres (miles) from Kidal.
"We are continuing our progress to secure the whole territory," he said, on condition of anonymity.
Two local elected representatives, also speaking anonymously because of the sensitivity of the topic, said there was fighting near Kidal.
- 'A lot of shooting' -
"Fighting has started -- there's a lot of shooting," one said, adding that large numbers of Wagner fighters, which the ruling junta called in two years ago, were present.
Another local official said "civilians are fleeing the city. We have to expect a lengthy conflict".
Some 25,000 people live in the Kidal desert area, a key site on the road to Algeria and a historic hotbed of insurrection.
The army had Thursday announced the start of what it termed "strategic movements aimed at securing and eradicating all terrorist threats in the Kidal region".
A large military convoy stationed since early October at Anefis, some 110 kilometres to the south, set off towards Kidal.
Tuareg rebels took up arms again in August and the population have since braced for a confrontation.
The Tuaregs previously launched an insurgency in 2012, inflicting humiliating defeats on the army before agreeing to a ceasefire in 2014 and a peace deal in 2015.
The uprising in 2012 coincided with insurgencies by radical Islamist groups who have never stopped fighting Bamako, plunging Mali into a political, security and humanitarian crisis that has spread to neighbouring Burkina Faso and Niger.
The withdrawal of a UN peacekeeping mission since the army took power has added to instability.
One officer spoke Saturday of fighting near to a Kidal camp which the UN force recently vacated.