Ten people spent Tuesday night in jail after they broke in and shut off valves for five pipelines carrying oil from Canada to the U.S.
Members of Climate Direct Action carried out the protest at pipeline flow stations in Washington, Montana, Minnesota and North Dakota.
The move was an act of support for the Standing Rock Sioux Tribe, which is actively opposing construction of the Dakota Access pipeline.
Activists with Climate Direct Action said they carefully researched how to safely shut down the pipelines, which carry oilsands product from Alberta to the U.S.
Five people initially risked arrest to shut off the valves, but videographers and other supporters were eventually detained too.
Photos and video of the action show the activists breaking in, cutting padlocks and turning off valves at numerous sites before they were arrested.
These pipelines have emergency shut off valves for a reason. And this is an emergency. Emily and Annette just shut down Enbridge Line 4 and 67 in Minnesota... in coordination with actions that shut down the other three pipes that bring tar sands into the US. #shutitdown #keepitintheground #notarsands
Enbridge shut down its Line 4 and Line 67 pipelines in response to "tampering incidents" at stations in Minnesota, a company spokesperson told The Globe and Mail.
"The actions taken to unlawfully trespass on our facility in Minnesota and attempt to tamper with energy infrastructure were reckless and dangerous," the spokesperson said.
"The groups involved in this morning's activities claim to be protecting the environment, but they do they opposite and put the safety of people at risk — including themselves, first responders and neighbouring communities and landowners."
Other infrastructure targeted in the act included Spectra Energy's Express pipeline, Kinder Morgan's TransMountain pipeline and TransCanada Corp.'s Keystone pipeline, Reuters reported.
Together, these pipelines can carry almost 3 million barrels of oil per day.
There were no reports of damage due to the action. But it nevertheless drew strong criticism from Canadian Energy Minister Jim Carr.
"Tampering with energy infrastructure is a dangerous activity and it could cause harm to citizens and surrounding communities, which is unacceptable," he said.
Climate Direct Action called on U.S. President Barack Obama to invoke an emergency order to keep the pipelines from operating, in an effort to wean the country off of fossil fuels.
"There is no plan of action, policy or strategy being advanced now by any political leader or environmental organization playing by the rules that does anything but acquiesce to ruin," Ken Ward, one of the protesters, said in a news release.
But that call wasn't heeded; all five pipelines resumed operations on Wednesday, Reuters said.
She was released later that day.