Police continue to arrest environmentalist protesters at the White House

United States Park Police arrested another gaggle of protesters outside of the White House Monday. The protesters were participating in an ongoing demonstration against the proposed Keystone XL pipeline.

Police arrested 52 protesters for blocking the sidewalk in front of the White House, the third round of mass arrests since the protests began on Saturday. The protesters are calling on President Barack Obama to reject the Keystone XL pipeline — a proposed expansion of an existing line that would transport crude oil from the Athabasca Oil Sands in Alberta, Canada, to refineries in Illinois and Oklahoma, and down to the U.S. Gulf Coast.

So far 162 people have been arrested since the protest began Saturday. The event, Tar Sands Action, will continue through Sept. 3. More than 2,000 people have registered to take part in the sit-ins.

Environmentalists contend the pipeline will damage the areas it runs through, such as the Nebraska Sandhills, and contribute to carbon emissions. The protesters at Monday’s demonstration wore pro-Obama buttons and called on the president to honor his campaign promises.

“Obama said he was going to take care of the environment,” said Brad Teal, one of the demonstrators. “And now we’d like to get him to honor that commitment.”

“I canvassed and knocked on doors for Obama, and he promised he would stand up to big oil,” said Jamie Nolan, the communications director of the Chesapeake Climate Action Network. “He can’t let us down.” (RELATED: EPA’s new ozone regulations overburden local governments, say critics)

The protesters, however, appear to be directing their non-violent resistance at the wrong government building. When asked for comment on the demonstrations, White House spokesman Clark Stevens said the pipeline project is currently being reviewed by the State Department.

“The State Department is assessing the project on behalf of the federal government,” Stevens said. “That process is ongoing, including receiving important input from the public and stakeholders. I would refer you to the State Department for details on the review process.”

President Obama is on vacation on Martha’s Vineyard.

The United States Park Police did not respond to calls for comment.