Police in Langley, B.C., have dismantled a grow-op made from five shipping containers buried under a fake farmyard, in the second such bust since last month.

Three men and a woman were arrested at the scene on Saturday and released pending further investigation, said Sgt. Lindsey Houghton of the Combined Forces Special Enforcement Unit.

Police also seized a loaded handgun in a bedroom, he said.

The operation, with about 430 pot plants, is believed to be linked to the Hells Angels motorcycle gang. But police said the operation is likely not connected to the underground grow-op found under a fake horse paddock in rural Mission in May.

To power the Langley grow-op, a nearby natural gas pipeline had been cut into and a bypass installed to direct gas to an industrial-sized generator worth about $100,000, police said.

"The property above the bunker was constructed to resemble a small hobby farm, complete with three sheep and one pig," Houghton wrote in a statement.

A dozen pit-bull type dogs and chihuahuas found on the property were removed by a family member of one of the suspects.

"Each of the steel shipping containers had a doorway cut through it to make a continuous pathway that connected all of the containers, as well as raised walkways so workers could easily walk through the bunker from container to container," he added.