Transport links in east London have been disrupted after violent clashes broke out Thursday morning between Extinction Rebellion activists and commuters.
A dramatic footage showed commuters dragging an activist from the roof of a London Underground train.
"Arrests have already been made and officers are working to quickly resume services," the police said in a statement.
Extinction Rebellion launched a wave of protests on October 7 to highlight the risks posed by climate change.

Britain working with allies to support shipping through Strait of Hormuz
Five Iranian women's soccer players granted humanitarian visas in Australia
Almost 700,000 displaced after Israeli strikes on Lebanon, UN agencies say
Iran fighting back but not stronger than U.S. thought, top U.S. general says
British warship HMS Dragon departs for Eastern Mediterranean