Pipeline protesters attempted to remove burned out vehicles blocking the Backwater Bridge on Highway 1806, which led to an hours-long standoff with police using water cannons to repel protesters on Sunday night.
The bridge has been closed since Oct. 27. Multiple vehicles burned there that night as law enforcement pushed protesters out of the northern "front line" camp atop the pipeline route and back to the main camps near the Standing Rock Indian Reservation.
Authorities have said the bridge may be unsafe for traffic due to the fires. Protesters criticize the barricade as blocking emergency services and suggest it is being used to prevent access to construction sites just north.
As of 1 a.m., about 100 to 200 protesters remained at the bridge where about 400 people were gathered several hours earlier, according to the Morton County Sheriff's Department.
Throughout the night, protesters started a dozen fires and tried to move north through a line of police, according to the sheriff's department, who reported that rocks and logs were thrown at officers, and one officer was struck in the head.
According to the sheriff's department, the incident began around 6 p.m. and one arrest was made as of 8:30 p.m. The sheriff's department is characterizing the protesters as "very aggressive" and said they have attempted to "flank and attack the law enforcement line."
Dallas Goldtooth, an organizer with the Indigenous Environmental Network, reported Sunday night that police sprayed protesters with a water cannon and used tear gas and concussion grenades to repel the protesters. It was 26 degrees in Cannon Ball at 9 p.m. He said the fires reported by police were set in order to help people warm up who had been sprayed.
Rob Keller, spokesman for the Morton County Sheriff's Department, confirmed that water was being used for crowd control as well as to douse fires and wet the land to keep the flames from spreading.
Goldtooth said numerous people have been struck in the head with rubber bullets and one person was in cardiac arrest from a direct hit.
The Cannon Ball gym has been opened for emergency relief, and EMTs from Standing Rock and the Cheyenne River Sioux Tribe, the reservation directly south, are providing support, Goldtooth said.
Goldtooth said activists have been frustrated with the barricade for weeks. It has blocked access for emergency services heading south to the camp and protesters heading north to demonstrate at the pipeline construction sites near the Missouri River, he said. The site where Dakota Access plans to drill under the river is about one mile north of the bridge.
"Folks have a right to be on a public road," he said by phone Sunday night. "It's absurd that people who've been trying to take down the barricade now have their lives at risk."
He said part of the intention of taking the vehicles away Sunday was to show the police force staged behind them — even if protesters still could not cross the bridge block, which has been reinforced with wire and cement jersey barriers.
"We hope that we're able to demonstrate that clearly with photos," he said.
Authorities have said the bridge is closed due to concerns about its structural integrity since the vehicle fires in October.
Keller wrote in an email that the Department of Transportation has not been able to inspect the bridge due to ongoing protests there. He said burned vehicles have remained, because it would be unsafe for crews to remove them in the current atmosphere.
"At this time the environment is not safe with the close proximity of protesters from the camp that can make their way to the bridge in a matter of minutes," he wrote.
Aidoneus Bishop, a protester on scene who helped move a burned vehicle, said he was hit with a rubber bullet in the hand and back. He questions the logic of the barricade, which is set behind the vehicles on the northern part of the bridge.
'The only thing that makes sense is that it's blocked to keep us away from the pipe," Bishop said.
Tara Houska, an organizer with Honor the Earth, said over 200 people have been pepper sprayed, tear gassed or soaked with water.
"They're using everything and anything," she said.
Houska noted that police reinforced the roadblock of burned vehicles with barriers and wire behind the vehicles on the bridge after the October fires.
"This has been weeks and weeks of those vehicles on the road for no apparent reason, and it's a huge public safety risk. It's putting enormous pressure on the Standing Rock Sioux community and people who live and work in the area," she said.
Goldtooth said protesters negotiated with law enforcement to remove the barricade three weeks ago and were told that if they demonstrated there peacefully, it would be taken down. Several marches have taken place there in recent weeks.
Keller countered that protesters were asked to stay off the bridge to allow for the assessment.
"As long as protests and marches happen almost daily on the damaged Backwater Bridge it will not open due to the possible damage done," Keller wrote. "The protesters are the ones not keeping their word."
The 1,200-mile, four-state pipeline is intended to carry oil from western North Dakota to a shipping point in Illinois. But construction of the $3.8 billion pipeline has been protested for months by the Standing Rock Sioux, whose reservation lies near the pipeline route, and the tribe's allies, who fear a leak could contaminate their drinking water. They also worry that construction could threaten sacred sites.
Energy Transfer Partners has said no sites have been disturbed and that the pipeline will have safeguards against leaks, and is a safer method of transport for oil than rail or truck. The company has said the pipeline is largely complete except for the section under Lake Oahe.
On Friday, Kelcy Warren, the chief executive of Dallas-based Energy Transfer Partners, said the company is unwilling to reroute the pipeline.
The Associated Press contributed to this report.