The scheduled installation of interim local authorities in Mali's troubled north was postponed Saturday over disagreements on the choice of officials, holding up the tricky path to municipal polls.

Under the terms of a 2015 peace accord which ended a three-year Tuareg rebel-led uprising hijacked by jihadists, the interim body was to begin work in the former rebel bastion of Kidal and four other regions.

But they face violent disagreement over several nominations to the authority, official sources said.

"In the interests of peace, the Malian government has decided to postpone the installation ceremonies of the interim authorities," a ministry of administration official told AFP.

"We have learned there have been hostile demonstrations since yesterday in certain northern localities owing to the installation of these authorities," the official added.

Once they can begin their mission, the authorities will represent the north's inhabitants until security improves sufficiently to allow local elections.

They are also supposed to work towards getting thousands of displaced people, who fled their homes during the unrest, to return.

The launch of the interim administration had been subject to long delays prior to talks last week between the government, pro-Bamako militias and the former rebels which finally yielded a definitive timeline for them to start work.

The agreement included the naming of ex-separatist rebels to posts in Timbuktu and the region of Menaka while also providing for joint patrols between regular troops, pro-government militia and former rebels from Monday in Gao and February 28 in the northern town of Kidal.

Pro-government militia received a post in Gao while the government nominated a Bamako-based businessman to head the regional assembly in the Taoudenni region.

But several armed groups threatened to protest in the ancient city of Timbuktu against the planned rollout, highlighting schisms within the country's complex web of militias.

A resident of the ancient city told AFP there had been demonstrations on Friday and Saturday, adding: "We don't agree. These people are being foisted on us."

The protests came against a backdrop of jihadists continuing to sow unrest, with dozens killed in the northern city of Gao last month by a suicide bomber targeting pro-government and ex-rebel militia preparing joint patrols.

Ever since the peace deal was signed, rival armed groups have repeatedly violated the ceasefire, threatening attempts to give the north a measure of autonomy to prevent separatist uprisings.