A 73-year-old woman in a wheelchair and an 81-year-old priest were arrested at a Just Stop Oil protest in Parliament Square on Wednesday, the group said.
Ten activists with the eco group were detained after refusing to leave the road and stop slow marching at around 11am.
The group said that among those arrested were Ari Rox, a 73-year-old retired cook.
The Met Police confirmed a “number of arrests” had been made.
Ms Rox, who has used a wheelchair for the past fifteen years, said in a statement: “I’ve come to London to join the Just Stop Oil march for my children and grandchildren.
“They are the ones who are going to have to face the mess that is being imposed on us in Britain, by our illegitimate government.
“We’re not asking that all oil is immediately stopped. We are simply asking the government to stop issuing new licences for oil, gas and coal.”
Roughly 66 supporters of the group began their protest at Parliament Square around 10.45am, causing disruption by slow marching in the road.
Police began to clear the road around 11am, ordering protesters to stop the slow march under Section 12 of the Public Order Act.
A Met Police spokesperson said: “At 11.16hrs, Section 12 conditions were issued to Just Stop Oil protestors, slow marching in the road at Parliament Square.
“By 11.30hrs, they had moved off the road, and traffic was moving. A number of arrests were made.”
Earlier Wednesday, protesters with the group brought rush hour traffic to a standstill around Hammersmith.
A police officer was filmed dragging a Just Stop Oil protester in a bid to clear the road.
A Met Police spokesperson said officers “dealt swiftly” with the protesters, reopening the roads close to West Kensington station, including Cromwell Road.
