National Policing Lead for Drugs Chief Constable Andy Bliss said:
"Cannabis is illegal because it is considered to be harmful. It is the police's job to enforce the law and continue to arrest and prosecute offenders for these type of offences.
"I want to make it clear that drug dealing is not a glamorous lifestyle - cannabis cultivation causes harm in terms of fire risks, theft of electricity, associated anti-social behaviour and violence sometimes involving firearms. Drug dealing at primary schools is uncommon and if reported will be treated very seriously.
"Police forces and the National Crime Agency (NCA) are finding that these criminals are going to ever greater lengths to conceal their illicit activity because they know that across the country we are shutting down these farms on a daily basis."