Daryl Hannah says being arrested was "the point" of her recent protest.

The 50-year-old actress was taken into police custody last month after participating in a sit-in demonstration outside the White House in Washington DC to campaign against a proposed oil pipeline from Canada to the Gulf Coast, but she insists she was aware of the risks she faced before agreeing to take part.

She said: "We knew there was a strong likelihood of it. That was sort of in a way the point because social movements have always taken some measure of civil resistance. You look at the Civil Rights Movement, or the Antislavery Movement, civil disobedience has played a large point in initiating those changes and getting people to actually say, you know what, I'm willing to risk my own freedom for greater freedom and in this case it was the freedom from fossil fuels."

While Daryl - who has previously been arrested twice, during protests in 2006 and 2009 - was calm about the situation, she admits others were frightened and she did her best to calm them down.

She added to America's OK! magazine: "If you see pictures of me from the arrest you will see I was smiling and I think that was part of me just trying to let them know it was OK.

"In the paddy wagon one of the ladies was really nervous and her glasses fell off and I was able to sort of wrangle my hands somewhat free and get her glasses back for her. They just saw that I was relatively calm going through the process and so it kept them calm I think."