The base in Suffolk was put in 'lockdown'.
Shots were fired as a man tried to force his way into a US air base in eastern England, say police.
The base - at Mildenhall in Suffolk - was put into 'lockdown' after the incident, which happened around 1.40 pm on Monday.
Suffolk Police said "shots were fired by American service personnel' before a man was arrested and taken into custody.
He suffered 'cuts and bruises' in the incident. No other people were injured.
Britain's Ministry of Defence said it was aware of an incident at the base and that police were taking a lead in the case.
The 1,162-acre base, which houses about 3,100 U.S. military and an additional 3,000 family members, is set for closure after the U.S. said it was going to move is operations from the base to Germany.
The US embassy declined immediate comment.