The San Francisco Police Department discovered substances to make explosives near an RV park Friday night.
"On Jan. 15 2021 at approximately 5:11pm, we responded to the 600 block of Gilman Ave to assist Federal Agents with an investigation. FBI agents on scene located compounds used to produce explosives," the police department announced on Twitter.
"The resident of an RV was arrested and nearby residents were evacuated," they added.
In Google Maps, the address provided by the authorities is recorded as being on the same block as Candlestick RV Park.
"This appears to be an isolated incident and the investigation was turned over to the department. Residents which were evacuated are receiving necessary assistance with temporary shelter."
They said the investigation is continuing and is in its first phases. No more information is now available.
The news comes as law enforcement officers across the country are on high alert after the U.S. Capitol assault on Jan. 6 and forward of President-elect Joe Biden's inauguration on Jan. 20.
