OUAGADOUGOU (Reuters) - Burkina Faso’s military has launched an investigation after a rights group accused the army of carrying out executions during a recent operation in which it said it had killed nearly 150 militants, the government said on Thursday.

The army said in February it had killed 146 militants in response to an attack on civilians, part of a broader response to worsening Islamist and interethnic violence across northern Burkina since last year.

Human Rights Watch said later that some of those killed were executed in front of their families. On Wednesday, a local rights group cited witnesses as saying 60 of the dead had been summarily executed.

Analysts are concerned that such abuse could fuel spiraling instability in previously peaceful Burkina. In neighboring Mali, jihadist groups have tapped into ethnic rivalries and anger with the central government to recruit.

In a statement, the Burkinabe government said the army was committed to human rights, and for the first time said it had “taken note of the allegations and assures that investigations are ongoing into the facts”.

However, “while waiting for the results of the investigations by the military justice system, the version of the facts is the one communicated by the military,” it added.

The government has acknowledged some abuses in the past and pledged to take action.

The Burkina Movement for Human and Peoples’ Rights (MBDHP) said on Wednesday it had visited the sites of the February anti-militant operation and interviewed witnesses.

“Of the 146 terrorists the military said it had killed, the MBDHP has identified 60 victims. All the 60 identified victims had been summarily executed,” MBDHP President Chrysogone Zougmore told reporters.

Thousands of people have fled their homes as a result of militant attacks and reprisals by the Burkinabe army, HRW said in a report last May.

Burkina declared a state of emergency in several provinces in December following an attack by an al Qaeda-linked group. The state of emergency was extended by six months in January after an outbreak of ethnic violence killed dozens.

Abuses by state forces present a dilemma for Western powers, including former colonial master France and the United States, which have deployed thousands of troops to West Africa’s Sahel region to help local governments counter al Qaeda and Islamic State-linked groups.

(The story corrects spelling of rights activist’s surname in paragraph 9)