Five bodies thought be the remains of soldiers murdered over their allegiance to overthrown Malian president Amadou Toumani Toure were exhumed near the capital Bamako on Sunday, a judicial source told AFP.

Yaya Karembe, the judge investigating war crimes committed during a coup in 2012 which plunged Mali into chaos, had the bodies dug up from two communal graves, the source said.

"We are announcing the discovery on Sunday by a team led by Judge Yaya Karembe of two mass graves containing bodies of five soldiers," the source, who witnessed the discovery, told AFP.

He said the men were discovered with their hands tied behind their backs.

They were located during the interrogation of a soldier over the murder of "red berets" loyal to Toure, a source within the investigation told AFP.

"The inquiry continues. There has been a confession which allows us to go faster with the investigation," the source said.

Twenty-one bodies found on December 4 in a mass grave near Bamako, were also believed to be red berets.

That discovery came a week after the arrest and detention of Amadou Haya Sanogo, leader of the March 22, 2012 coup against Toure.

The government says Sanogo has been charged with complicity in kidnappings, but a source close to the judge in the case told AFP the charges also include murder, complicity to murder and carrying out kidnappings.

Fifteen people, mainly soldiers from his inner circle, were arrested immediately after him.

Sanogo's coup toppled what had been heralded as one of west Africa's most stable democracies and precipitated a crisis in which Al-Qaeda-linked groups seized control of the country's north, enforcing a brutal form of Islamic law until a French-led military intervention forced them out.

On April 30, a group of red berets loyal to Toure staged a failed counter-coup in which about 20 of them were killed by Sanogo's "green berets". Their bodies were never found.

In the months that followed the coup, Sanogo's then-headquarters in the central town of Kati were the scene of abuses and killings carried out against soldiers seen as loyal to Toure.