Gail Bradbrook climbed onto the top of the entrance of the transport ministry

Climate change activists, including one of the founders of Extinction Rebellion, targeted Britain's transport ministry in central London on Tuesday to protest against a proposed high-speed rail project known as HS2.

Gail Bradbrook, one of the founders of the group, climbed onto the top of the entrance of the transport ministry and put up a sign reading "HS2 is our climate emergency" above the revolving doors.

Bradbrook, invoking the example women's suffrage activist Emmeline Pankhurst, then tried to smash one of the ministry's windows with a hammer and screwdriver. She was later brought down by a police climber.

"Rebels have glued themselves to the building and co-founder, Gail Bradbrook has climbed on top of roof at entrance in civil disobedience due to our government complicit inaction on the climate and ecological emergency we are facing," Extinction Rebellion said.

Extinction Rebellion, which uses civil disobedience to highlight the risks posed by climate change and the accelerating loss of plant and animal species, is midway through a new two-week wave of actions in cities around the world.

Police ordered a halt to all Extinction Rebellion protests in London on Monday after a week action, saying those who did not comply would be arrested. They have already made almost 1,500 arrests since the protests began.

The group said High Speed 2 project (HS2), aimed at improving links from London to central and northern England but which is billions of pounds over budget and running late, would damage or destroy 108 ancient woodlands.

A spokesman for the transport ministry declined immediate comment on the action.

Another activist tried to lock herself to the transport ministry but was arrested.

"Everybody who is not paying attention is numb at the moment. We all use tactics to numb ourselves because this is scary," the arrested woman said.

She said the high speed rail project would be a "scar across the belly of this land" and that it would destroy vital woodlands and wildlife habitats.

The project aims to slash journey times between the capital and Birmingham, which supporters say would give Britain the kind of fast rail services enjoyed by other major countries.

An independent review is considering whether it should go ahead given that it would cost around 88 billion pounds ($111.5 billion) under current estimates.