Protesters from the Just Stop Oil group were arrested at the National Gallery and at a sensitive London landmark on Monday.
About 100 demonstrators were arrested near the Cenotaph – the key site for Remembrance Day services which the government wants to be immune from protest – as they held a slow-walk demonstration on busy roads around Whitehall.
One officer said the protesters were moved to near the Cenotaph “to get them off the road”.
Prime Minister Rishi Sunak and Home Secretary Suella Braverman have demanded the Cenotaph be free from protest and warned people at pro-Palestine rallies against damaging it.
A few hundred metres away, two more protesters were arrested inside the National Gallery, where they smashed the glass covering a painting on display.
They used hammers to break the glass protecting the Rokeby Venus painting.
Police said activists had been arrested on suspicion of criminal damage.
The artwork, painted by Diego Velazquez in the 1600s, was previously slashed by suffragette Mary Richardson in March 1914.
Just Stop Oil named the protesters as Hanan, 22, and Harrison, 20, and said their actions were to demand the government immediately halts all new oil and gas projects in the UK.
“Women did not get the vote by voting; it is time for deeds not words. It is time to Just Stop Oil,” the group said.
“Politics is failing us. It failed women in 1914 and it is failing us now. New oil and gas will kill millions. If we love art, if we love life, if we love our families, we must Just Stop Oil.”
Police said most of the slow-walk arrests happened between Trafalgar Square and Parliament Square
“Around 100 arrests were made by officers along Whitehall during another day of disruption by Just Stop Oil,” a police statement said.
“No protester glued themselves to the road. There were no offences linked to the Cenotaph."
Police have the government's “absolute and total backing” to tackle criminality, Mr Sunak said after objections to a pro-Palestinian march due to take place on Armistice Day.
Concerns have been raised about the demonstration due to take place in central London on Saturday, although the planned route will pass the Cenotaph, instead going from Hyde Park to the US embassy.
Speaking to broadcasters on Monday, the Prime Minister said: “Remembrance Day is a time for national reflection. It is a time when I know the whole country will come together to pay tribute to those who have paid the ultimate sacrifice to keep us safe.
“I want to make sure police have our absolute and total backing to clamp down on any acts of criminality, but also to ensure public order.”
Ms Braverman was holding a meeting to discuss the issue on Monday.