MANILA — More than 40 people were killed and a school district supervisor was kidnapped in separate episodes around the island of Mindanao, days after a landmark peace deal was struck with the largest Muslim insurgency group in the Philippines, officials said Wednesday.

The bloodiest battles involved a group opposed to the peace deal, but military commanders said that the timing of the fighting was not related to the announcement of the peace agreement and that it was initiated by police officers and soldiers trying to arrest rebel fighters.

“There is no direct link between the signing of the peace agreement and this operation,” Col. Ramon Zagala said in a phone interview. “But it has an effect on the peace process. We consider this group to be a spoiler to the peace agreement.”

On Saturday, the Philippine government finalized the details of a peace agreement with the Moro Islamic Liberation Front that would give the group control over an autonomous area of Mindanao and let it share the wealth from the area’s resources in return for the rebels gradually giving up their weapons. The deal seeks to end decades of violence in the area and bring economic growth to the struggling region.