Clitheroe residents are being warned not to be alarmed by booms of cannon to be fired twice daily from the castle grounds from today until Friday.
The warning has been issued by Clitheroe Police.
A spokesman for Ribble Valley Police said: "Just to inform Clitheroe residents that cannon fire will be heard from the Castle at 12pm and again at 2-30pm. This twice daily event will take place all week from today until June 21st.
"The castle is running a schools event on Castle Life. Didn’t want the town’s folk thinking we are under attack!"