Gardena authorities raid underground casino operations.

Early Thursday, GARDENA, Calif. (KABC)– Gardena cops raided a structure they said was serving unlawfully as an underground casino.

More than a dozen individuals were seen being detained after the raid, resting on the curb with hands cuffed behind their backs.

Next-door neighbors tell Eyewitness News that brand-new occupants moved into the red-brick building in the 1700 block of West 134th Street about a month earlier.

Since then, individuals were seen in and out of the structure at all hours of the day and night.

One man informed Eyewitness News he had been inside the building just the night before the raid.

“It resembles a casino,” said Shamil Harvey of Las Vegas, adding that individuals discover the operation through word of mouth.

Another next-door neighbor reported hearing numerous surges during the early-morning authorities raid, most likely flash-bang grenades used to stun people as SWAT officers moved in.

Police did not release more in-depth information about the raid or if any arrests were made. The examination is continuous.