London climate-change protesters vow to continue blockades

Police talk to protesters as they block traffic on London's Oxford Circus, Thursday, April 18, 2019. The group Extinction Rebellion is calling for a week of civil disobedience against what it says is the failure to tackle the causes of climate change. (AP Photo/Vudi Xhymshiti)

Co-founder of Extinction Rebellion Dr Gail Bradbrook poses for the media on Waterloo Bridge, in London, Thursday, April 18, 2019, as she says protests will escalate if its demands are not met. Climate change protesters glued themselves to a train and blocked major London intersections Wednesday, on the third day of a civil disobedience campaign. Three demonstrators were arrested after stopping Docklands Light Railway services at Canary Wharf station. Several others glued themselves together outside the house of opposition Labour Party leader Jeremy Corbyn. (Lewis Pennock/PA via AP)

Protesters who have blocked London roads and bridges for more than three days say they will escalate their civil disobedience campaign if the British government doesn't step up action against climate change.

Hundreds of demonstrators have blocked sites including Waterloo Bridge over the River Thames and the Oxford Circus and Marble Arch intersections since Monday.

The protest sites have sprouted tents, sound systems and even an ice cream van. Traffic is snarled and bus routes have been disrupted, to the frustration of commuters.

Police have made more than 420 arrests.

Gail Bradbrook of protest group Extinction Rebellion said Thursday that "more people are joining us all the time."

Home Secretary Sajid Javid says protesters "do not have the right to break the law and significantly disrupt the lives of others."