OAKLAND — Four men were arrested Friday in the takeover robbery of a marijuana cultivation business in East Oakland, authorities said Saturday.

Pounds of marijuana taken in the robbery were recovered. There were no reported injuries.

The robbery happened just after 4 p.m. Friday at a building in the 900 block of 86th Avenue where seven people were working at the time. Police said the four men, one simulating a gun, forced their way in, threatened the employees and grabbed pounds of packaged marijuana.

Police were alerted by someone outside the building of a possible robbery and responded as the suspects were fleeing.

The suspects, three men from Richmond and one from Oakland who are all in their 20s, were all found within a few hours.

After questioning, they were arrested on suspicion of robbery of an inhabited dwelling.

Authorities did not say how large the operation was or if the facility had proper permits to cultivate marijuana.