There have been upwards of 15 tremors over the last day in East Bay, according to figures from the United States Geological Survey (USGS).
East Bay is the eastern region of the San Francisco Bay Area, home to Oakland, Danville, San Ramon and San Leandro.
Earthquake activity in the region has been extremely active over the last few days.
Was the Bay Area hit by an earthquake just now?
The most recent quake to rock the Bay Area was at 4.48pm GMT (8.48am PT).
The most recent quake to rock the Bay Area was at 8.21pm GMT (12.21am PT).
Measuring 2.8 magnitude, the tremor was recorded 2km east of Danville, California.
There have been 15 quakes in the Danville area as of 9pm GMT time (1pm PT time), with five measuring above 2.5 magnitude.
Prior to that, the most significant quake for some hours was a 3.3 magnitude one, which struck at 1.28pm GMT (5.28am PT) 2km east of Danville.
Two minutes afterwards, Bay Area reporter Will Tran tweeted: “Breaking-just felt magnitude 3.5 earthquake while reporting in Danville, CA. 530am. Car rocked side to side for about two secs @kron4news.”
Train servicer provider SFBart also said it halted travel on its Pittsburgh/Bay Point lines for several minutes to check for any track damage.
Amy Vaughan, a geophysicist, later told the San Francisco Chronicle: “Looking in that general region, I’m counting 55 quakes just in the last week.”
“Of those, this 3.3 was the largest, but there were several in the two range and even one other at 3.0.”
The Danville area has been rattled by a number of small earthquakes this week.
On Monday, a 2.9 magnitude earthquake was recorded close to the town’s Monte Vista High School. This was followed by a 2.5 earthquake.
Will a big earthquake hit the Bay Area?
Concerns have been raised that the area is due another massive quake.
San Francisco’s Bay area sits in Northern California and is above the dangerous San Andreas Fault Line, which is prone to earthquakes.
California is located on the active Ring of Fire, a major area basin in the Pacific Ocean known for its earthquake and volcanic activity.
On April 18, 1906, a 7.8 magnitude earthquake struck San Francisco, killing 3,000 people and destroying 80 percent of the city.
However, Brian Kilgore of the US Geological Survey told NBC Bay Area this week there’s no evidence that swarms indicate a large quake is coming.
Kilgore said large earthquakes have not followed swarms in previous years.