A man was arrested Monday after apparently trying to drive onto a Royal Air Force base in eastern England used by the U.S. Air Force.

Police in Suffolk, England, said U.S. service members fired shots during the incident and that a man was detained with cuts and bruises. Nobody else was injured. The suspect's motive remained unclear.

CBS News partner network BBC News cited the Ministry of Defense as saying the incident involved an individual trying to force his way through a checkpoint in his vehicle.

Crown Prosecution Service undated handout photo made available Friday April 1, 2016 of delivery driver Junead Khan, 25, from Luton England. AP

A brief mandatory lock-down of the base was lifted.

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A British delivery driver was convicted last year of plotting to attack American military personnel at Mildenhall and another nearby air base. A jury found Junead Khan guilty of preparing an act of terrorism.

The 25-year-old's work for a pharmaceutical firm took him past the U.S. air bases in eastern England and prosecutors said Khan, who was arrested in July 2016, had exchanged online messages with an Islamic State of Iraq and Syria (ISIS) fighter in Syria.

They discussed attacking military personnel after faking a road accident outside the bases.