Protesters have climbed a 270ft construction site crane just streets from the White House and unfurled a banner calling for resistance to President Donald Trump.
Officers called to the construction site in Washington found that three people had attached themselves to the crane and another four people joined them, Captain Robert Glover of the Metropolitan Police Department’s special operations division told reporters.
The protesters told police they are conducting a First Amendment action, he said.
“Time is on our side,” Mr Glover said. “Safety is our foremost mission this morning.”
After a few hours, several protesters dangling from the horizontal arm of the crane opened the 70ft by 35ft orange and yellow banner that reads “resist”.
The protesters are calling for resistance to Mr Trump and his agenda, Greenpeace spokesman Travis Nichols said.
It is a continuation of protests that began with Mr Trump’s inauguration.
Greenpeace said in a statement that the protesters are “calling for those who want to resist Trump’s attacks on environmental, social, economic, and educational justice to contribute to a better America”.
The protest comes a day after Mr Trump’s administration moved to delay implementation of at least 30 environmental rules and froze new Environmental Protection Agency contracts and grant awards.
“While we respect everyone’s right to protest, today’s actions are extremely dangerous and unlawful,” police said in a statement posted on Twitter.
Police would consult with prosecutors about appropriate charges, Mr Glover told reporters.
There was no continuing threat to anyone outside the site and minimal disruption to the area, he said.