France has condemned "violence and extra-judicial arrests" committed against black citizens in Kidal in northestern Mali, calling on all parties there to exercise restraint.
"We are getting reports of arrests and violence in the Kidal area, notably concerning the songhaï, peul and bella communities, because of the colour of their skin" said Philippe Lalliot, spokesperson for France's ministry of foreign affairs.
He called for the release of those detained, expressing his wish that a negotiated solution be found to the situation in Kidal, and asking "all parties concerned" to respect human rights.
On Sunday, residents of Kidal told journalists that members of the MNLA tuareg rebel movement had attacked black people in the town, in an attempt to drive them out and towards Gao, further south.
MNLA spokesperson Mossa Ag Attaher denies that the group is targeting black residents and insists instead that it is searching for "infiltrators" sent by the Mali authorities.
The group says several dozen people, including an officer in the Malian army, have been arrested by its fighters in Kidal.
Mossa Ag Attaher, was speaking from Ouagadougou, where he was taking part in talks organised by the mediating country, Burkina Faso, about the organisation of presidential elections at the end of July in Mali.
At the request of the Malian president, in January France's president François Hollande ordered French forces to intervene in Mali, to stop the advance of islamist fighters southwards towards the capial, Bamako.
The islamists in the north were in alliance with some Tuaregs who want autonomy and resent the Bamako authorities.
There has long been animosity and suspicion between the nomadic, lighter-skinned Tuareg people in Mali and the darker-skinned population.