LONDON, Oct 2 (Reuters) - British police investigating a suspected plot involving an airbase used by the US to target Iran have arrested a dual UK-Iranian national on suspicion of preparing terrorist acts, the latest twist in a largely unexplained incident.
Below is what is known so far:
WHAT HAPPENED?
Police were called to RAF Fairford, 90 miles (145 km) west of London, early on Sunday morning, arresting five suspects who were then released on bail a day later.
A local farmer had called police, saying
she saw three large white vans parked near the base and a group of "hooded and masked men" running into a field nearby. The Times reported that another witness who also contacted police was one of the five arrested.
Armed officers responded to the calls and made the arrests in the Whelford area, about a mile from the base, before evacuating nearby properties and searching three vehicles.
The five were initially arrested on suspicion of offences under the explosives act and later on suspicion of preparation of a terrorist act.
WHAT HAPPENED NEXT?
US President Donald Trump said those involved in the plot had planned "big damage" while US Secretary of State Marco Rubio also pointed to the "hands of a foreign actor".
In July, Iran's Revolutionary Guards had said the base was a legitimate target.
British counter-terrorism police later confirmed they were considering whether a foreign state had been involved, before Prime Minister Andy Burnham announced on Wednesday there might have been an Iranian link.
A 25-year-old dual UK-Iranian national was arrested in London on Thursday, in what police called a "hugely complex" investigation.
WHAT HAS IRAN SAID?
Iran has said accusations it was involved were baseless and on Thursday summoned the British ambassador in Tehran over the issue.
WHAT ELSE DO WE KNOW?
Police said no explosive devices had been found as part of the investigation, but a quantity of petrol had been recovered during searches of the vehicles.
The five men detained were all British nationals aged between 23 and 25 who lived in London, police said.
An image on social media purported to show some of the suspects sitting on the floor shirtless with hands behind their backs after their arrest. Reuters was unable to independently locate and verify the source of the photograph.
Following their release on bail, police said the five remain under investigation and are subject to stringent conditions on their movement and contact with others.
WHY WOULD FAIRFORD BE A TARGET?
Fairford, which opened in 1944 and was used by allied troops for the D-Day invasion of Normandy, has this year been used by US forces for strikes on Iran.
It is one of the US Air Force's only European airfields suitable for heavy bombers, and played a key role in both the first Gulf War in 1991 and the invasion of Iraq in 2003.
Britain said in July its armed forces were ready to protect Fairford after Iran's Revolutionary Guards warned it not to allow US bombers to fly from the base. The Guards said any base used to launch attacks would be a legitimate target.
Over the last six weeks there has been increased surveillance in the area after a specific threat from the Iranians, according to a local councillor.
(Reporting by Sarah Young, editing by Andrew Cawthorne and Gareth Jones)
