Hundreds of water protectors were injured at the Standing Rock encampments Sunday evening when law enforcement blasted them with water cannons in freezing temperatures.

The attacks came as water protectors used a semi-truck to remove burnt military vehicles that police had chained to concrete barriers weeks ago, blocking traffic on Highway 1806. Water protectors' efforts to clear the road and improve access to the camp for emergency services were met with tear gas, an LRAD (Long Range Acoustic Device), stinger grenades, rubber bullets and indiscriminate use of a water cannon with an air temperature of 26 degrees Fahrenheit.

"It is below freezing right now and the Morton County Sheriff's Department is using a water cannon on our people, that is an excessive and potentially deadly use of force," Dallas Goldtooth of Indigenous Environmental Network said.

Some flares shot by law enforcement started grass fires which were ignored by the water cannons and had to be extinguished by water protectors. Law enforcement also shot down three media drones and targeted journalists with less lethal rounds.

National Lawyers Guild legal observers on the frontlines have confirmed that multiple people were unconscious and bleeding after being shot in the head with rubber bullets. One elder went into cardiac arrest at the frontlines but medics administered CPR and were able to resuscitate him. The camp's medical staff and facilities are overwhelmed and the local community of Cannonball has opened their school gymnasium for emergency relief.

The Standing Rock Sioux Tribe's Emergency Medical Service department arrived on scene to administer medical services. The Cheyenne River Sioux Tribe also sent Emergency Medical Service vehicles to the Oceti Sakowin Camp to assist. Hundreds are receiving treatment for contamination by CS gas, hypothermia, and blunt traumas as a result of rubber bullets and other less lethal ammunition.

"Tribal EMS are stepping up and providing services that should be the responsibility of Morton County, this is ridiculous," continued Goldtooth. "Because of the police enforced road block, ambulances now have an extra 30 minutes to get to the hospital. Those are life and death numbers right there, and Morton County and the State of North Dakota will be responsible for the tally."

The military vehicles blocking the bridge were burned in a blockade fire on Oct. 27, after law enforcement raided and cleared the "1851 Treaty Camp," an occupation of the pipeline corridor and reclamation of unceded territory. Despite the obvious public safety risk, and despite promises from Morton County that they would clear the road, law enforcement has insisted on keeping the vehicles on the bridge for weeks.

"For weeks, the main highway to the Standing Rock Sioux Reservation has been cut off, with no movement by the state to address a public safety risk," Tara Houska, national campaigns director for Honor the Earth, said. "Attempting to clear the road was met with police spraying people with water cannons in 26 degree weather—that's deadly force, it's freezing outside. They want to kill people for clearing a road? When will our cries be heard? Stop the Dakota Access Pipeline. Respect the rights of indigenous people, of all peoples."

This obstruction of Highway 1806 threatens the lives of the water protectors and residents of the Standing Rock Sioux Reservation, as emergency services have been needed but unable to reach camp quickly. The blockage also unjustly restricts the free movement of local residents and hurts the Tribe economically by cutting off travel to and from the Prairie Knights Casino. Images of the burned vehicles have fed negative, distorted and sensationalist media portrayals of the encampment.

"Standing Rock is the moral center of the nation right now; the real question is why there's no response from the White House to kind of abuses that would make us protest loudly if they happened abroad," Bill McKibben, founder of 350.org, said. "This is America's oldest shame, and it's sad that we're still seeing it in the waning days of the Obama presidency."

Greenpeace's spokesperson Mary Sweeters agrees. "The violent scenes at Standing Rock last night were nothing short of horrific. It is clear that the militarized police response has completely disregarded the protection of human life," she said.

"Law enforcement put people's lives in danger last night as water protectors attempted to clear a path for emergency services to reach the camp. President Obama must step in to stop the pipeline and end the violence immediately. This is about standing up for Indigenous people's rights and sovereignty. This is about ensuring Standing Rock's survival by protecting its water supply and land. It is time to do the right thing before more damage is done."