Police arrested a man at a US air base in Britain on Monday after a car drove into a checkpoint gate, prompting American military personnel to open fire, officials said.
Suffolk Police in eastern England said the incident at RAF Mildenhall - home to the US Air Force's 100th air refuelling wing - was "ongoing" but that there was "no wider threat to the public or occupants on the base". Mildenhall, around 70 miles (110 kilometres) north-east of London, was briefly locked down over the incident before reopening at 2:35 pm (1435 GMT), a spokesman for the base confirmed.
Local police said they were called at around 1340 GMT to reports of a "disturbance", adding: "The base was put into lockdown and units responded immediately.
"Shots were fired by American service personnel and a man has been detained with cuts and bruises and taken into custody.
"No other people have been injured as a result of the incident." Suffolk Police said area schools would continue to operate as normal.
A government source said the incident was sparked by a car trying to force its way through a checkpoint at the base. A Ministry of Defence spokesman said: "We are aware of an incident at the entry point of RAF Mildenhall."
Mildenhall said on its website: "RAF Mildenhall locked down at 1pm (1300 GMT) today following reports of a disturbance on base." The precise nature of the incident remained unclear mid-afternoon Monday.
The base was at the centre of a foiled terrorism plot in 2015. A British man who plotted an Islamic State-inspired attack on American military personnel based there was jailed for life last year.
Junead Khan, who was a committed supporter of the IS group had used his job as a delivery driver for a pharmaceutical firm as cover to scout several US Air Force bases in eastern England between May and July 2015, including Mildenhall.