Hundreds of cannabis plants have been seized after a dawn raid at a former pub in Heywood.
Officers executed a warrant at the now closed down Three Terriers early on Monday morning.
Locals said a large number of police vans could be seen surrounding the old boozer on Bridge Street.
Police have confirmed a cannabis farm was found inside the building which is understood to have been boarded up for several months at least.
In a statement Greater Manchester Police said: "Shortly after 7am on Monday 10 February 2020 police executed a warrant at a premises on Bridge Street, Heywood.
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"Officers uncovered a quantity of cannabis plants and cannabis cultivation equipment.
"No arrests have been made.
"Enquiries are ongoing."
The Manchester Evening News understands an estimated 500 plants were recovered.
Eyewitnesses said engineers from the electricity board could also be seen going in and out of the building at the same time as police.
Anyone with information is asked to call police on 101.
