Attacks in Burkina Faso against Christians and other civilians are "war crimes" that the government must do more to stop, Human Rights Watch (HRW) has said.
Hundreds of civilians, including many Christians, have been killed in attacks by armed Islamist groups in Burkina Faso in the past year.
HRW condemned the violence as it called on the government to take action to stem the bloodshed.
"Armed Islamist groups in Burkina Faso have attacked civilians with unmitigated cruelty and utter disregard for human life," said Corinne Dufka, HRW's West Africa director.
"Deliberately targeting farmers, worshippers, mine workers, displaced people and traders are war crimes."
HRW has documented 256 civilian deaths in targeted attacks and summary executions by armed Islamist groups since April 2019.
Witnesses told the organisation that the attackers have sought to justify their killings by linking victims to the government, the West or Christian beliefs.
They told of civilians being gunned down in marketplaces, villages, churches, mosques and while transporting aid to displacement camps.
HRW spoke to 54 victims and witnesses of abuses in Burkina Faso's capital, Ouagadougou, in November and by telephone in December 2019. The attacks documented took place between April and December 2019.
The organisation said that the groups responsible have come from neighbouring Mali, first gaining a foothold in Burkina Faso's northern Sahel region before spreading in the last few years to the Nord, Centre-Nord, Boucle du Mouhoun, and Est regions.
The groups are allied with al-Qaeda and include Ansaroul Islam and the Islamic State in Greater Sahara.
"The Islamist armed groups need to immediately end their attacks on civilians," Dufka said.
"At the same time, the Burkina Faso government should take stronger steps to protect vulnerable communities from harm and impartially investigate and appropriately prosecute those implicated in war crimes."