Vandals have allegedly burned sections of the Dakota Access Pipeline in South Dakota and Iowa in recent incidents, authorities in those states said Tuesday.

Someone used a torch to cut open a piece of the 1,172-mile oil pipeline on March 13 or earlier in Iowas Mahaska County, Sheriff Russell Van Renterghem told The Associated Press. There was a similar complaint on March 17 about a section in South Dakotas Lincoln County, AP reported.

No injuries were reported and no one has been arrested in either disturbance. Authorities say the burn holes are in empty sections of pipe, AP said.

Questions arose about possible attacks on the 1,172-mile oil pipeline after company attorneys filed a heavily redacted status report Monday that said the project had been targeted by vandals.

Due to recent coordinated physical attacks along the pipeline that pose threats to life, physical safety, and the environment, the remainder of this status report is filed under seal, attorneys for the developer Energy Transfer Partners wrote in a court document.

The company has provided updates about construction during a federal lawsuit against the pipeline brought by Native American tribes.

The recent damage does not appear to have significantly delayed completion of the pipeline .

These coordinated attacks will not stop line-fill operations. With that in mind, the company now believes that oil may flow sometime this week, the status report said.

ETP officials have accused protesters multiple times of damaging company property and attacking workers during months of confrontations.

In many respects, tensions over the pipeline are lower now than theyve been in months. The camps of self-proclaimed water protectors have largely cleared, lowering the chance for more of the large-scale protests in North Dakota, where police and demonstrators had clashed repeatedly since last summer.

What remains of the conflict is the court battle over the pipelines validity.

The Standing Rock Sioux and Cheyenne River Sioux oppose construction of the pipeline under the Missouri River in North Dakota, because they argue that it violates an 1851 treaty, was improperly evaluated for environmental hazards and violates their religious freedom.

Theyve sued Energy Transfer Partners and the Army Corps of Engineers, the government agency that had authority over the pipeline, in U.S. District Court in Washington. Theyve lost a series of motions in recent weeks that sought to block the company from filling the pipeline while the lawsuit unfolds.

Energy Transfer Partners says that the pipeline is safer environmentally than shipping oil on trains and trucks and that they received all necessary government approvals.

Under President Donald Trump , the Army Corps of Engineers granted a final permit to ETP. That permit reversed a decision by the Obama administration to block ETP from building near the Sioux reservations.