Most of those detained were quickly released without any charges, while three were released on bail pending an investigation, The Guardian reported. Under English law, police can arrest those they believe plan "imminent" violence.
In Facebook postings, EDL members have threatened to set fire to the tents around St. Paul's Cathedral if the protesters were still camped there Sunday, which is Remembrance Sunday, when England honors its war dead, Bryn Phillips of Occupy the London Stock Exchange said. The Metropolitan Police said investigators had also received information about a possible Armistice Day attack on the encampment.
Friday's arrests were made near the Cenotaph, the monument in Whitehall to fallen British service members.
"It is fantastic if they are using their resources to try and stop people getting on to this site," Phillips said of the arrests. "If this has prevented violence then I am pleased."
He said the Facebook threats were read to protesters Friday morning to make sure they were aware of a possible attack.
2014: The Year in Music [PHOTOS]