Police arrested Robert F. Kennedy Jr., his son Coner Kennedy, and actress Daryl Hannah on Wednesday for civil disobedience against the Keystone XL pipeline initiative.

A host of environmental activists showed up at a climate change rally in Washington, D.C. to end plans for the Keystone XL pipeline which would funnel synthetic crude oil from Canada to various locations in the United States, according to The Huffington Post.

Robert Kennedy Jr., an attorney with the Natural Resources Defense Council, urged leaders in the U.S. to end the controversial pipeline project that was first proposed in 2008.

 "The science is clear. Climate change is not just an economic issue, it is a moral issue. I do not believe that Keystone XL will happen," the elder Kennedy said, according to The Washington Times. "I believe that President Obama and Secretary Kerry will do the right thing. And we need to show our support."

Sierra Club Executive Director Michael Brune and 350.org founder Bill McKibben were also among the 48 people that were arrested.

This is not the first time that Kennedy Jr. was arrested for supporting the environment.

Kennedy Jr. served 30 days in jail in 2001 for trespassing as part of a protest against Navy bombing exercises in Puerto Rico's Vieques Island, according to Newsday.

The Keystone XL project is supported by the American Petroleum Institute (API), an oil industry lobbying group, that believes the project is necessary and will create new jobs for the country.

The Christian Science Monitor quoted API President Jack Gerard who stated Keystone XL "the most thoroughly vetted major infrastructure project in the nation's history" and that all the special conditions necessary to ensure the safety of the environment will be upheld.

The rally on Wednesday will allegedly be followed by a larger on planned to take place at the National Mall on Sunday.

Additional photos of the civil disobedience were posted on the Sierra Club's Flickr account.

Tags: robert f kennedy jr. conor kennedy Keystone XL Pipeline