BAMAKO: The Malian army said it had killed around 50 militants during an operation in which it managed to rescue some of the soldiers who were captured during deadly attacks last month on two bases in the centre of the country.

Unidentified assailants killed 38 soldiers during the September 30 attacks, among the heaviest losses for Mali's army this year as it struggles to repel increasingly brazen raids by militant groups, some with links to al Qaeda and Islamic State.

"Around 50 enemy neutralised, around 30 wounded, and equipment destroyed," the army said in statement detailing the results of its counter-operation.

The army said it had freed 36 of around 60 of its soldiers who were missing following the September raids. Their relatives have protested over the high death toll and a lack of information on the casualties and those missing.

The West African country has been in conflict since 2012 when Islamists hijacked an ethnic uprising by Tuaregs in the north. The violence has since moved to central Mali, from where jihadist fighters launch attacks across the Sahel region.

In a further example of the spiralling insecurity, pro-government Tuareg militia GATIA on Saturday said six of its fighters had been killed in an overnight raid on a GATIA outpost by unidentified assailants in Mali's northern region of Kidal.

The situation has raised concerns that the under-funded regional G5 force, comprising troops from Mauritania, Mali, Niger, Chad, and Burkina Faso, is unable to stop unrest spreading from West Africa's restive hinterland to coastal countries including Ivory Coast and Ghana.