Insulate Britain has targeted Canary Wharf as it renews its roadblock campaign after a pause.
Demonstrators from the environmental group obstructed the Limehouse Causeway at the junction with the A1206 at 8.20am on Monday.
Other protesters targeted Bishopsgate and Upper Thames Street.
A total of 61 of activists sat in the road carrying Insulate Britain banners, and some glued themselves to the road surface.
Members of the public argued with demonstrators as police detained them and dragged them out of the road.
The group posted on its website at 8.30am, coinciding with the start of the demonstrations, with the message: “We won’t stand by while the Government kills our kids.”
In a statement, activist Liam Norton branded the Government “treasonous”, claiming it has “betrayed” citizens and is leading the country on a path to “genocide”.
He said: “We know that the public is frustrated and annoyed at the disruption we have caused.
“They should know that one way or another this country will have to stop emitting carbon. We can do that now in an orderly, planned way, insulating homes and preventing thousands of deaths from fuel poverty, or we can wait until millions have lost their homes and are fighting for water or starving to death.”
Protester Tony Hill, who claimed to be a former police officer, soldier and councillor, and said he had travelled from near Kendal in Cumbria to join the protest in Bishopsgate, said Insulate Britain’s call to insulate all UK homes is a “no brainer”.
Police removing Insulate Britain protesters after they blocked a road near Canary Wharf in east London.
Victoria Jones
The 71-year-old said: “I’m here today out of anger, fear and determination. The anger that my Government is failing the people of our country. The governments of the world are failing everyone. Everyone says we’re at the 11th hour but we’re at midnight and nothing substantial is being done by our Government and governments across the world.
“We’re saying insulate as many buildings as we can. It’s a no brainer. It’s something we can all do, it’s a solution.
“We’ve got the money; all we need is the willpower from our Government to do it. It will save money, create jobs, save lives and save the planet.
“Why aren’t they doing it?”
Members of the public heckled protesters blocking the road at the junction of Bishopsgate and Camomile Street in central London.
One man, who shouted as he walked by, said: “We all have jobs to go to.”
Another walked up to the protesters, looked down and said: “What are you doing in the middle of the road? I can’t get to work.”
Insulate Britain, an offshoot of Extinction Rebellion, wants the Government to insulate all UK homes by 2030 to cut carbon emissions.
It blocked roads on 14 days over the five weeks to October 14, with activists often gluing their hands to the carriageway to increase the length of time it took for police to remove them.
Hundreds of arrests were made, with some people detained several times.
The campaign continues despite injunctions leaving protesters facing court summons and possible imprisonment or an unlimited fine.