Heavy gunfire was heard early on Friday at the main military base outside Mali's capital Bamako before easing after about an hour, a Reuters reporter said.
Three residents of the camp, who asked not be identified, said they believed the base at Kati, about 15 km (10 miles) outside Bamako, had been attacked by Islamist militants, who have been waging an insurgency in Mali for the past decade.
The Kati base was the site of mutinies in 2012 and 2020 that led to successful coups, but the residents said the soldiers did not appear to be fighting among themselves.
Islamist militants linked to al Qaeda and Islamic State have repeatedly attacked army bases across the country but never so close to the capital.
The army said late on Thursday that al Qaeda-linked militants had attacked several military camps earlier in the day several hundred kilometres north of Bamako in central Mali, killing one soldier and wounding 15.
Reuters could not immediately verify the cause of the gunfire at Kati. Mali's military spokesman was not immediately available for comment and an official at the presidency declined to comment.
After the gunfire subsided around 6 a.m. (0600 GMT), helicopters could be heard circling above the base. The entrance was closed off and two ambulances were seeing driving past.
The junta that rules Mali came to power in an August 2020 coup that began as a mutiny at the Kati base. It staged a second coup in 2021 to force out a civilian interim president who was at odds with the leader of the first putsch, Colonel Assimi Goita.
Goita then became interim president. He plans to continue to lead a transitional government until elections are held in 2024.
His government has sparred repeatedly with neighbouring countries and international powers over election delays, alleged army abuses and cooperation with Russian mercenaries in the fight against the Islamist insurgency.
Despite coming to power pledging to stamp out the insurrection, the junta has been unable to prevent the insurgents from extending their operations further south from their havens in the north and centre.
Last week, unidentified armed men killed six people at a checkpoint just 70 km east of Bamako.