Police, who first arrived on the scene at 9pm on Friday night, were initially delayed from searching the two terraced houses in Montagu Street because of fears that a neighbouring house was structurally unsafe.

A number of residents and businesses were asked to vacate their properties while the pavement was cordoned off.

But a structural engineer gave the go-ahead this afternoon and officers were able to recover around 160 saplings from one property, around 180 larger plants from the other and equipment associated with the harvesting of the plant.

Insp Vaughan Clarke said: "Having received intelligence we wanted to take the supply out of the hands of the dealers.

"We wanted to make sure the buildings were safe and a number of businesses closed at our request.

"Drugs are a real priority for us and we will target anyone who commits these offences."

The third property which was checked by the engineer is not believed to be involved in the operation.

No arrests have been made at this stage.