The Federal Bureau of Investigations is reportedly looking into another fire along the Dakota Access Pipeline (DAPL) route in Iowa.
According to KCCI, the FBI is investigating a fire that was set at a construction site along the DAPL’s route in Jasper County.
Work crews arrived at the construction site on Saturday night and found several machines on fire.
A backhoe and two bulldozers at the site were severely damaged by the flames, KCCI said.
Assistant Chief of the Reasnor Fire Department Don Steenhoek told KCCI that he believes protesters may be behind the fire.
Chris Merten, the owner of the property where the blaze occurred, told KCCI that the incident was the second fire in three months.
Neither Energy Transfer, the owner of the DAPL, nor the FBI have commented on the matter.
Police also suspected arson was the cause of three fires along the pipeline’s Iowa route in August.
Jasper County Chief Deputy Duane Rozendaal told WHOTV in August that “all evidence” points to arson at two sites in Jasper County and one site in Mahaska County.
The fires damaged at least $1 million worth of equipment in Newtown and Reasnor that belonged to construction firms hired to work on the line.
Environmentalist and Native American groups have staged several protests along the pipeline’s route.
Last week, federal officials reiterated a request that Energy Transfer continue to hold off on construction activity within 20 miles east or west of Lake Oahe in North Dakota.
The request was made after a U.S. federal court ruled against the Standing Rock Sioux Tribe, a Native American group that was seeking an injunction to halt the project.
The Standing Rock Sioux Tribe filed a lawsuit against the Army Corps earlier this year that alleged the Corps violated environmental and historical preservation laws when it approved the pipeline.
Last month, the U.S. Department of Justice, the Department of Interior and the Department of the Army halted construction at a portion of the line on Army Corps of Engineers land bordering or under Lake Oahe.
The Army Corps said last week that it expects its review of the matter to be complete “soon.”
According to memo from Energy Transfer CEO Kelcy Warren, construction on about 60 percent of the pipeline had been completed as of early September.
The $3.7 billion pipeline is expected to be online in late 2016.