Police have made 61 arrests in the run-up to a major arms fair being held in London.
Up to 60 protest groups are expected to demonstrate
Protesters have been arrested on charges ranging from fly-posting, swimming in the Royal Docks and chaining themselves to Woolwich bridge to conspiracy to commit violent disorder.
The latest arrests came on Monday after two protesters broke into BAE Systems' office in Carlton Gardens, south-west London and chained themselves to a desk.
Sixty protest groups are expected to try to disrupt the Defence Systems Equipment International (DSEI) show at the Excel centre in London's Docklands, which begins on Tuesday.
It is thought they will try to stop the exhibition through sit-down protests or by shutting down the nearest Docklands Light Railway station.
Many have set up headquarters at a hall a mile away from the exhibition where signs on the doors read: 'No cops, journos or cameras' .
Police have been taking photographs of demonstrators
Protester and author Gideon Burrows told BBC London the secrecy was necessary.
He said: "The protesters themselves have come together in an attempt to stop this fair from taking place and that necessarily entails secret plans, so that you are not stopped from doing so by the police or by security."
The four-day event is expected to attract thousands of top military and government figures from around the world.
Policing the show is likely to cost £1m and anti-terrorism officers are being put on standby in case of violence.
Paul Beaver, a spokesman for the fair, denied any "torture weapons", cluster bombs or landmines would be on sale, although tanks and helicopters are on show.
He said: "It is like any other trade exhibition, it is like the motor show in Birmingham or exhibitions at Earl's Court, this happens to be for the defence industry."