Mali's military and allied militias killed at least 31 people in attacks on two villages in the central Segou region, where the main insurgent group linked to al Qaeda operates, Human Rights Watch (HRW) said in a report on Tuesday.

The first attack took place on October 2 in the village of Kamona, where the army and militia forces killed at least 21 men and burned homes, the HRW report said.

The second, it reported, occurred in the village of Balle about 55 km (34 miles) away, where at least 10 people, including one woman, had been killed.

The report said witnesses described army and militia forces executing villagers after accusing them of collaborating with Jama'at Nusrat al-Islam wal-Muslimin (JNIM). The al-Qaeda-allied group has expanded operations in the south of the West African country.

The witnesses included a local herder who survived after hiding in an abandoned home with his nine-year-old daughter, and later found 17 bodies riddled with bullets, HRW said.

The African Union and a spokesperson for Mali's army did not immediately respond to requests for comment.

New York-based HRW called on the Malian authorities to investigate the killings and urged the African Union to take steps to help end the conflict and hold parties accountable for crimes.

Landlocked Mali is under pressure from jihadist groups that have persistently attacked state forces and, in recent months, imposed a fuel blockade that has led to long queues at fuel stations and made access to diesel generators more expensive.

Mali's foreign minister this week dismissed as implausible the notion that jihadists could soon take the capital Bamako.