There are few details regarding the incident, but rumours spread on social media have alleged that the group of people went missing after an army control near the village of Maliemana, in central Mali.

"We haven't heard from them," said the father of one of the missing people, who declined to be named, adding that he had heard that his relatives had been killed.

Mali is struggling to contain an Islamist insurgency spread across the north and centre of the country, in a conflict which has killed thousands, inflamed ethnic tensions, and in which its own army has been accused of abuses.

Mali's army released a statement on Sunday night confirming that soldiers arrested "suspects" in the area on December 19.

However, it added that it released the suspects after the mayor of nearby village of Dioura intervened.

"Since then, there have been wild rumours of a disappearance," the army said.

Residents of the area, for their part, have said that they have seen dead bodies that were stuffed down a well.

"I saw 24 bodies, which came out of the well," said Amadou Balobo, a Dioura resident.

He added that the alleged victims were from the village of Maliemana who were travelling to the weekly market.

AFP was unable to independently confirm the claims.

Investigators from Mali's military police visited the area on Sunday but they said the well pointed out by villagers was in fact the remains of an old village.

The army said in a statement that the investigators "found nothing, neither well nor bodies".

However, the UN mission in Mali also has an open investigation into the case, according to a diplomat who declined to be named.

An army official, who also declined to be named, told AFP that the military was in contact with the UN regarding the matter.