Almost 150 people were extrajudicially killed by Malian and Burkinabe security forces in Mali between April and June, the UN said Thursday.
A 2012 revolt in northern Mali has since spread to the centre of the poor Sahel country, as well as to Burkina Faso and Niger despite the presence of thousands of French and UN troops.
The Mali-based United Nations mission, MINUSMA, reported "an increase in serious human rights violations attributable to the Malian security forces", which it held responsible for 94 such killings over the three-month period.
The quarterly report also found 50 extrajudicial killings in late May by Burkina Faso troops in the village of Boulkessi, and settlements close to the nation's Mali border.
The UN report said the army targeted numerous terrorist elements in central Mali, as well as sometimes conducting "reprisal operations against civilian populations", accused of supporting jihadists.
Malian authorities have said they will investigate to find those responsible.
MINUSMA also voiced concern at the number of military operations carried out with local Dozo militiamen.
These traditional hunters have previously been accused of carrying out illicit operations.
Central Mali saw a surge in violence from 2015, when the Islamic preacher Amadou Koufa founded the Katiba Macina militia, recruiting widely from the Fulani community.
Jihadist groups in Mali were found to be responsible for 43 murders, 25 kidnappings and attacks on schools and humanitarian spaces between April and June, according to the UN report.