London CNN  — 

At least 276 Extinction Rebellion protesters have been arrested in London as campaigners begin two weeks of demonstrations demanding that governments take action on the climate and ecological emergency.

The Metropolitan Police said 276 people had been detained by 6:15 p.m. (1:15 p.m. ET) as activists shut down roads around Parliament and across large parts of Westminster in the UK capital.

The action is part of a larger coordinated movement called International Rebellion; protests are expected to take place in 60 cities worldwide.

Activists gather on Westminster Bridge during the protests.

“Despite a culture of fear being spread by (the) government in the run up to the Rebellion – several thousand people … blocked sites, roads and locations across Westminster,” Extinction Rebellion wrote online.

“There is no Plan(et) B. The government doesn’t have one. The things we trust in life that we don’t even know we trust, they’re all incredibly fragile. Extreme weather will tell this truth for us unless the government does it for us first.”

Climate change activists block The Mall as they demonstrate near Buckingham Palace.

Protesters created roadblocks, marched down The Mall (which leads to Buckingham Palace), locked themselves to vehicles and took over tourist hotspots to play music and chant.

As of 5:45 p.m., Extinction Rebellion said in a statement that it still had a presence in eleven sites across Westminster “with people returning tomorrow to continue the rebellion.”

Protestors had blockaded the north and south ends of Westminster Bridge, which is by the Houses of Parliament, according to the statement.

The statement added that animal activists had taken over Smithfield Market, a wholesale meat market in London, where they staged a sit-in and set up plant-based food stalls.

Extinction Rebellion called for more provisions amid an uptick of arrests and confiscations by the police, appealing to “more Londoners to join us as we head towards a chilly evening.”

It added that some of the protestors were preparing “to go on hunger strike to illustrate that our just-in-time food system is too fragile to repeatedly withstand the shocks of extreme weather happening in other parts of the world.”

Among the demonstrators arrested on Monday was 83-year-old Phil Kingston, who spray-painted the message “Life, not death for my grandchildren” on the side of Britain’s finance ministry building.

Police officers detain climate change activist Phil Kingston outside the UK Treasury.

Last week Kingston was one of several demonstrators who used a fire engine to spray 1,800 liters of fake blood at the Treasury, in protest at what the group says is the UK’s contradictory stance on tackling climate change.

“The protest is being held to highlight the inconsistency between the UK Government’s insistence that the UK is a world leader in tackling climate breakdown, while pouring vast sums of money into fossil exploration and carbon-intensive projects,” an Extinction Rebellion statement said.

Kingston has been arrested multiple times while protesting with Extinction Rebellion, and said Monday that he refuses to “stand by … and will willingly accept imprisonment.”

Extinction Rebellion says it expects the next two weeks of action to be “at least five times larger” than the protests held in April, which saw activists take over locations such as Parliament Square, Oxford Circus and Waterloo Bridge. More than 1,000 activists were arrested at the time.

The group says its key demands for this protest are for the government to declare a climate and ecological emergency, halt biodiversity loss and reduce greenhouse gas emissions to net-zero by 2025 and to “create and be led by the decisions of a Citizens’ Assembly on climate and ecological justice.”