Four Palestine Action activists have been charged over a break-in at RAF Brize Norton, which saw military planes vandalised.
An estimated £7million of damage was caused when two Voyager aircraft – a type of mid-air refuelling plane – were sprayed with red paint, a trademark of the direct-action protest group.
The suspects, all aged between 22 and 35, were named as Amy Gardiner-Gibson, Jony Cink, Daniel Jeronymides-Norie and Lewie Chiaramello.
The latter pair are both from London, while the former two were listed as having no fixed abode.
Another man was released without charge, while a 41-year-old woman was released on bail after being arrested on suspicion of assisting an offender.
A spokesperson for Thames Valley Police said: “Counter Terrorism Policing South East (CTPSE) has charged four people as part of an investigation into an incident in which damage was caused to aircraft at RAF Brize Norton, Oxfordshire.
"Following authorisation from the Crown Prosecution Service (CPS), the [suspects] were charged today with conspiracy to enter a prohibited place knowingly for a purpose prejudicial to the safety or interests of the United Kingdom, and conspiracy to commit criminal damage.
"The charges are in connection with an incident in the early hours of Friday 20 June in which damage totalling around £7m was caused to two aircraft at RAF Brize Norton.”
The four suspects will appear at Westminster Magistrates’ Court later today.
Police also confirmed that the CPS would be arguing that the alleged offences “have a terrorist connection”.
While it is not currently a terrorist group, MPs voted by a margin of 385-26 last night to back a motion to proscribe Palestine Action under the Terrorism Act 2000.
The measure will be scrutinised by the House of Lords today but, if it is passed, it would make membership of the group or attempts to drum up support for it illegal.