Fighting resumed Sunday between the Malian army and Tuareg separatist and rebel groups in the country's northern region, military officers and elected officials said.
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.
One military officer told AFP that the Mali army has "resumed operations on the ground to secure the entire national territory."
A local elected official, also speaking under the condition of anonymity, said that "fighting has resumed near Kidal" and locals could "hear sounds of rockets".
Fighting had begun a day earlier as the army closed in on the area, after announcing Thursday that it was starting "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 (68 miles) to the south, set off towards Kidal.
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.
Some 25,000 people live in the Kidal desert area, a key site on the road to Algeria and a historic hotbed of insurrection.
Residents have been braced for a confrontation since the Tuareg rebelllion took up arms again in August.
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.