Mali’s new leader, Dioncounda Traore, has threatened a “total war” against separatist rebels in the north.
Mr Traore’s inauguration marks a return to civilian rule following last month’s coup in the West African state.
Mr Traore now has 40 days to organise elections - though correspondents say this deadline is unlikely to be met because of the situation in the north.
Since the coup, Tuareg and Islamist militants have taken control of much of the northern desert region.
The UN says there are continuing reports of civilians being killed, robbed, raped and forced to flee northern rebel-held areas.
“Reports also suggest that tensions between different ethnic groups are being stirred up, increasing the risk of sectarian violence,” the UN human rights commissioner Navi Pillay said in a statement.