Daryl Hannah has been arrested in front of the White House along with other enviromental protesters.
The 50-year-old Splash star was rallying against a planned oil pipeline from Canada to the US Gulf Coast.
The Keystone XL pipeline would go through six states to refineries in Texas.
Before she was detained, Daryl told WRC-TV the protesters want to be free from the "death and destruction" that fossil fuels cause.
The group is calling for clean energy instead.
She sat down on the pavement near the White House and refused orders from the police to move.
She has been arrested for environmental causes in the past.