The raids saw equipment from three premises being seized. The news comes before the environmentalist group plan a weekend of protests in the capital. One of the locations that was aided was a warehouse used by the group.
Another location was an arts centre that was exhibiting some of the structures used in last year’s blockade of newspaper printing plants last year.
Extinction Rebellion has planned further protests against the owners of the UK’s press outlets this weekend.
It has been reported that they will unite with the Black Lives Matter campaign against racial injustice.
Scotland Yard in a statement said it had “taken proactive action to prevent and reduce criminal disruption which we believe was intended for direction at media business locations over the weekend”.
A spokesperson added that 12 people had been arrested in three raids across the capital.
The spokesperson said: “During the arrests, a number of items were seized by officers.
“These items included bamboo structures, lock-on equipment and other items.
“These items could be used to cause criminal damage and obstructions.
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Police have said protests are planned for Westminster, Lambeth and Southwark this weekend.
Extinction Rebellion has planned to gather midday on Sunday in Parliament Square in the centre of London.
The group said they were targeting “four tax-avoiding, climate sceptical billionaires, Rupert Murdoch, Lord Rothermere, Sir Frederick Barclay and Baron Evgeny Lebedev, who own 68 percent of the UK’s print media”.
Extinction Rebellion claims the media barons are “manipulating the truth and sowing division among the general public for profit”.
Speaking to the Guardian, one of the activists, Nuala Gathercole Lam, said: “This is what happens when you take peaceful protest action to the true centres of power in this country.
“Four billionaires control the lion’s share of our news and it affords them a vast corrupting influence over democracy.
“Not only have they become kingmakers in our elections, but they are standing in the way of a national conversation about how we meet the vast challenges the climate and ecological crises present for everyday life.”
Chief Inspector Joe Stokoe, from the Met police’s public order command, said: “We believe certain protest groups are specifically intending to disrupt some business locations or potentially cause criminal damage to property.
“If this happens, we will take further action as required to prevent offences being committed or deal with anyone committing criminal acts.
“Today, we took proactive action to prevent and reduce the likelihood of criminal activity during the course of the weekend.
“This action should further demonstrate our commitment and proactivity to preventing criminality.”
The group have claimed that Priti Patel is putting pressure on police to quell Extinction Rebellion demonstrations in case they target media organisations again.