HELENA, Mont. (AP) — Civil liberties advocates are taking Montana officials to court to force the public release of documents detailing the government’s planned response to anticipated protests against the Keystone XL oil pipeline.

The ACLU of Montana filed a lawsuit Thursday in state District Court in Helena against the Department of Emergency Services and the Division of Criminal Investigation. The American Civil Liberties Union alleges the two agencies are involved in a coordinated effort by federal and state officials to crack down on protesters if the pipeline is built.

State officials had no immediate response to the allegations, Montana Department of Justice spokesman John Barnes said.

The 1,200-mile (1,930-kilometer) Keystone pipeline is proposed by TC Energy of Canada. It would transport up to 830,000 barrels (35 million gallons) of crude daily from western Canada to U.S. refineries.

It was rejected under the Obama administration over climate change worries and other environmental concerns, but was revived when President Donald Trump took office.

According to the lawsuit, the two Montana agencies responded to a 2018 Freedom of Information Act request by producing heavily-redacted documents and imposing a gag order on the documents they did provide.

The ACLU sued federal officials on similar grounds in 2018 and last year waged a successful court battle against proposed laws in South Dakota meant to prevent disruptive Keystone XL pipeline demonstrations.

Officials have sought to head off a repeat of the kind of protests mounted against the Dakota Access pipeline in North Dakota that resulted in 761 arrests over a six-month span beginning in late 2016.