HAMILTON – Hamilton police are investigating multiple instances of tampering at an oil pipeline project in the city.Investigators provided few details about the incidents involving the Line 10 pipeline, which runs through Hamilton and is owned by Enbridge Inc. (TSX:ENB).The damage consisted of holes drilled into the pipeline, adding there have been multiple instances of trespassing in the past week, police said Thursday in a release. No other information was available.A 35-kilometre stretch of the Line 10 pipeline, which transports crude oil, is under construction as Enbridge looks to replace 30-centimetre steel pipe installed in 1962 with a more robust 50-centimetre variety.Shortly before police announced the investigation, a group purporting to fight on behalf of Indigenous people and the environment sent an email to the Canadian Press taking responsibility for various instances of damage to the Line 10 pipeline.The group contends it has been “sabotaging” sections of pipe since the replacement work began. They claim to have drilled holes of varying sizes in some sections of pipe and poured corrosive chemicals in others, but did not say if this occurred during the past week.“We do this in solidarity with the Indigenous peoples of this area. A people who have been displaced, threatened and murdered since early colonial arrivals — who still continue to face this violence,” the email said, adding that previously laid sections of Line 10 would have to be replaced because of prospective damage.Hamilton police would not comment on whether the group or its members were under investigation.Enbridge said in a statement that the recent damage involved tampering with stored pipe, but did not immediately address the claims from the group.“We treat these situations very seriously and will support the prosecution of anyone involved,” the company said. “Safety of the public, the environment and our workers is our top priority at Enbridge. Pipelines are no different than power lines or railway lines, and tampering with energy infrastructure puts people and the environment at risk.”Enbridge has said the replacement pipe will run parallel to the existing line, within the same right-of-way, for the majority of its length.The decommissioned segment of Line 10 will be “taken out of service safely and permanently, but left in place” when the new line is brought into service, it said in documents outlining the project.Police are urging anyone who witnesses trespassing on the Line 10 construction corridor to report it immediately.