Two pubs are to close for 48 hours after they were caught selling alcohol to underage volunteers during a test purchase operation.
The White Swan at Dronfield and The Whitecotes at Boythorpe, Chesterfield, sold booze to the teenagers for a second time in a three-month period.
Derbyshire Police and Trading Standards officers visited 12 premises across Chesterfield, Bolsover and North East Derbyshire and five failed.
Members of staff were issued with £80 fixed penalty notices for selling the alcohol.
A police drugs dog also visited bars and pubs in Chesterfield town centre as part of the same operation.
Ten people were searched and a 27-year-old man from Chesterfield was arrested on suspicion of possession of MCAT.
The Whitecotes will be closed for 48 hours from 4pm on Friday, February 21, and The White Swan will close for 48 hours from 4pm on Friday, February 28.
More test purchase operations are planned.