The Justice Department on Friday pledged to prosecute environmental activists who target oil pipelines and other energy infrastructure.

The Justice Department said it would vigorously prosecute those who damage “critical energy infrastructure in violation of federal law,” according to Reuters.

The statement was in response to letter sent by more than 80 House lawmakers last month asking Attorney General Jeff Sessions to explain whether the law covers domestic terrorism by environmentalists such as a group that tried to shut down oil pipelines in October 2016.

Activities who seek to “damage or shut down” pipelines put lives at risk, cost taxpayers millions of dollars and threaten the environment, a department official told Reuters Friday.

The Justice Department, however, did not say specifically how it would investigate or prosecute the activists with the group Climate Direct Action that attempted, but failed, to disrupt the flow of oil across four states.

The group had said it was acting in solidarity with the Standing Rock Sioux Tribe to protest the Dakota Access Pipeline. President Trump made permitting the pipeline a top priority of his administration during his first few weeks in office.

An industry coalition that supports pipeline development applauded the Justice Department decision, saying "ecoterrorists" jeopardize billions of dollars in infrastructure investment.

"There is a bright line between lawful and unlawful protest and we are pleased that the Department of Justice will recognize criminal acts done under the facade of environmental activism as exactly what they are: criminal acts," said Craig Stevens, spokesman for the Grow America's Infrastructure Now coalition.

"In order to modernize our nation’s infrastructure, we need billions of dollars in public and private capital," Stevens said. "That investment would be in peril if ecoterrorists are allowed to destroy public and private infrastructure projects with impunity. Hopefully the DOJ’s pronouncement will deter dangerous acts of protest in the future.”