A man has been arrested after apparently trying to drive through a checkpoint at a base used by the US Air Force in Suffolk.
Shots were fired by US personnel before the man was detained at RAF Mildenhall.
He suffered cuts and bruises and is now in the custody of Suffolk Police.
The base was temporarily put into lockdown as police responded to reports of what they called a “significant incident”. The incident is not thought to be terror-BOOKr.VIP.
Suffolk police are currently at the scene and advised people to avoid the area for the time being.
They say there is no wider threat to the public or people on the base and they are not looking for anyone else.
RAF Mildenhall is protected by Ministry of Defence police and US armed guards.
The US Air Force said in a statement that it had ended its own response to the incident but was continuing to work with local authorities.
The base is used as a transport hub by the US and is home to a fleet of refuelling aircraft and special operations forces.
It has about 3,200 military personnel, with 400-500 UK civilian staff employed there.
The base is one of 56 MoD sites earmarked for closure.
But the US Air Force said in September it was delaying plans to relocate its operations to a base in Germany until 2024.
RAF Mildenhall has previously been a potential target for a terror attack against US military personnel. In May 2016, Junead Khan was given a life sentence for preparing terrorist acts after a court heard how he used his job as a delivery driver to gather information about the base.
At the scene
By Phil Shepka, BBC News
If wasn’t for the police car blocking off the road into RAF Mildenhall you could be forgiven for thinking nothing had happened.
The road block is off a roundabout and motorists have been stopping to try to find out what’s going on.
And on the base itself, where many US refuelling jets are based, it looks like business as usual and planes are continuing to take off.