Approximately 130 officers took part in Operation Diffuse which targeted 12 properties in Swindon on Wednesday.
8 people were arrested on suspicion to supply class A drugs along with 1 arrest in London, and 2 in Bristol Prison.
£6000 and class A drugs were found buried in the back garden at one of the addresses.
“It’s gone extremely well, we’ve had 16 people that we wanted to arrest and so far we’ve got 11 arrested, so extremely successful,” said acting Det Insp Jim Taylor, from Swindon CID.