Climate-change activists in four states shut valves to five oilsands pipelines.

• Several climatechange activists were arrested on Tuesday after they attempted to shut five oil pipelines from Canada that can carry nearly 15 per cent of daily U.S. consumption, in the latest move by environmental groups to disrupt movement of oil across North America to heighten awareness of the dangers of pollution.

Protesters in Montana, Minnesota, North Dakota and Washington state were arrested after turning off valves on pipelines that flow from Canada’s oilsands into the United States, said Climate Direct Action.

The group also posted videos online showing the protesters breaking chains and turning the valves. It did not say how many people had been arrested and no confirmation was immediately available from police in the localities involved.

In a press release, the group said it had attempted to shut the pipelines in support of the Standing Rock Sioux Tribe, which has been protesting the construction of a US$ 3.7 billion pipeline carrying oil from North Dakota to the U. S. Gulf Coast over fears of potential damage to sacred land and water supplies.

“We are acting in response to this catastrophe we are facing,” Afrin Sopariwala, a spokeswoman for the group, told Reuters.

Together, the lines impacted can carry up to 2.8 million barrels of oil a day, equivalent to about 15 per cent of daily U. S. petroleum consumption.

The incident is the latest in a series of actions by environmentalists and others in response to growing concern over the effects of fossilfuel production on the environment and the potential effects of spills on land and livelihoods.

Sopariwala said protesters shut down the pipelines between 6: 30 a. m. and 7: 30 a. m. PT by manually shutting off valves. In some places they had to cut chains to reach the valves. She said the group had spent months researching how to safely shut down the pipelines.

Enbridge Inc. said that it temporarily shut its Line 4 and 67 pipelines at its valve site in Leonard, Minn., but that there would be no effect on deliveries. The company said in a statement the activists “are inviting an environmental incident” and endangering public safety.

Spectra Energy Corp., one of four companies said to be affected, said trespassers had tampered with a valve on its Express Pipeline in Montana and it had shut the line down as a precaution. It later said it was taking steps to restart it.

The other pipe lines claimed to have been shut in are TransCanada Corp.’ s Keystone pipeline and Kinder Morgan Inc.’ s Trans Mountain pipeline.

Trans Canada said its Keystone pipeline in North Dakota was shut down tem- porarily as a precaution after protesters tried to disrupt it.

Kinder Morgan confirmed trespassers broke into a location of one of its two Trans Mountain feeder lines in Washington state, but it was not operating that part of the pipeline at the time and no product was released. The company said the line has since reopened and deliveries on Trans Mountain were not affected.

In January Enbridge was forced to shut a crude pipeline in Ontario after a protester tampered with a valve station, while in December the company turned off another line in Quebec for several hours after activists chained themselves to equipment.

The most notable protest has been against construction of the 1,770- kilometre Dakota Access pipeline, a project spearheaded by Energy Transfer Partners that would carry oil from North Dakota’s Bakken shale play into Texas.

Construction of one section in North Dakota has been halted after protests and lobbying of the Obama administration. Permitting on that line is still under review and protests have continued. On Monday, 27 people were arrested in North Dakota including actress Shailene Woodley, who narrated her arrest on Facebook Live.

All Tuesday’s protesters and their support crews have been arrested, Sopariwala said, with police turning up 20 to 90 minutes after the valves were turned.

Carl Weimer, executive director at the i ndustry watchdog Pipeline Safety Trust, said the action was a “dangerous stunt.”

“Closing valves on major pipelines can have unexpected consequences endangering people and the environment. We do not support this type of action,” he said.