BAMAKO (Reuters) - Mali’s government has said it is investigating accusations by an opposition party that the army kidnapped and executed seven civilians in the center of the country last week.

The opposition SADI party accused the army of executing the men, who had been attending a religious celebration in the village of Nangarabakan in the Segou region on Feb. 21. The victims included an imam and family members of the village chief, SADI said.

In a statement late on Tuesday, the government confirmed that civilians had been killed during a search and sweep operation in central Mali, which has been ravaged by Islamist militants’ attacks, and that it had ordered an investigation.

“The government expresses its condolences to the bereaved families and reiterates its determination to pursue operations ... with strict respect for human rights rules and international humanitarian law,” the statement said.

Islamist groups seized control of Mali’s vast northern territories in 2012 before being driven back by a French-led military intervention. They have since regrouped and spread into the more populated center of the country, winning recruits by playing on local grievances such as rights abuses by the army.

A report by campaign group Human Right Watch last September accused the Malian military of conducting extrajudicial killings, kidnappings, torture and arbitrary arrests against suspected sympathizers of jihadist groups.

The government has acknowledged some abuses by its forces in the past but also rejects many allegations made by rights groups.

Islamist militants have launched increasingly frequent attacks on civilians, Malian troops and U.N. peacekeepers in the center of the country in recent months, expanding their reach beyond their stronghold in the desert north.

Six Malian soldiers were killed when their vehicle struck a land mine near the town of Dioura late on Tuesday, the army said in a statement, the latest in a series of mine attacks in the central Mopti region.

The army did not say who they believed to be responsible for planting the landmine.