BISMARCK, N.D. (AP) — Environmental activists who tried to disrupt some oil pipeline operations in four states to protest the Dakota Access pipeline say they aren't responsible for any recent attacks on that pipeline.

Dakota Access developer Energy Transfer Partners said in court documents Monday that there have been "coordinated physical attacks" along the $3.8 billion pipeline that will carry oil from North Dakota to Illinois. Company officials haven't responded to AP requests for more details.

Jay O'Hara with the Climate Disobedience Center told The Associated Press Tuesday that Climate Direct Action wasn't involved, and he isn't aware of anyone claiming responsibility.

In October, Climate Direct Action activists tried to shut valves on oil pipelines in North Dakota, Minnesota, Montana and Washington. But O'Hara says the group has no plans to target Dakota Access.

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