British prosecutors have charged two men under the National Security Act over an incident near RAF Fairford, a military airbase used by the United States Air Force in England.
The Crown Prosecution Service announced the charges on Tuesday against Mohmed Abdulkarim, 24, and Nouman Essghir, 24.
Abdulkarim is charged with engaging in conduct likely to materially assist a foreign intelligence service, while Essghir faces a charge of entering a prohibited place for a purpose prejudicial to the United Kingdom.
The charges relate to an incident on September 27, when police arrested five men after reports of suspicious vehicles near the base in Gloucestershire.
The incident prompted a major security response, with armed police officers and army bomb disposal experts deployed to the area. About 85 households were evacuated as authorities examined three vehicles.
Counter-terrorism police later said no improvised explosive devices were found, although petrol was recovered from the vehicles.
The investigation subsequently led to further arrests. Police have said they consider Iranian state involvement highly likely, but investigations into the circumstances and the extent of any involvement are continuing.
RAF Fairford has been used by US bombers for military operations against Iran. The United States withdrew bombers from the base following the incident.
The charges are allegations, and the defendants are presumed innocent unless proven guilty in court.