The ministry said Mali's ambassador had been called in to hear a "strong protest against the recent, recurring criminal acts" allegedly committed by the army following the disappearance of several citizens just over the border.

Dozens of people had demonstrated earlier in the day outside the presidency demanding revenge and an end to disappearances they said had bEen carried out by Mali's soldiers over recent days.

Protesters held up placards claiming the Mauritanians had been killed "in cold blood" in the border area south of Adel Bagrou, in the east of Mali.

Mauritanian member of parliament, Mohamed Mahmoud Ould Henenna, told the Alakhbar news agency at least 15 of his countrymen had been killed.

The government in Nouakchott promised to investigate, but there was no immediate response to the charges from Bamako.

Seven Mauritanians died in Mali in the same region, near Nara, in January. The Bamako authorities announced an inquiry and said there was no evidence linking the army to the deaths.

The ministry noted in a statement carried by the national news agency that a senior Mauritanian delegation had gone to Mali after the January deaths "to try to contain this hostile behaviour towards our citizens".

"Despite the assurances given" by the Mali authorities, their response had been "below expectations".

Mali has struggled to wrest control of territory from a jihadist insurgency that began in the country's north in 2012 and has since spread to neighbouring Niger and Burkina Faso, claiming thousands of lives.