The suspected attack occurred at midnight at the Akrotiri military base, with no injuries reported. The incident is described as "ongoing."
"The protection of our forces in the region is at the highest level," a Defense Department spokesperson said in a statement.
The incident occurred after Britain agreed on Sunday to let the United States use British military bases to carry out "defensive" attacks on Iranian missiles and their launch pads.
The UK has recently reinforced the base with, among other things, air defense, radar equipment and F-35 fighter aircraft.
