An earthquake with a magnitude of 4.3 rocked the San Francisco Bay Area early on Monday, waking up many people, with more than 22,000 saying they felt it, according to the United States Geological Survey.

The earthquake was just east-south-east of Berkeley, the survey said. It happened shortly before 3am PT.

People posted online that they felt their homes shake. Bay Area Rapid Transit (Bart) posted on X that trains were running at reduced speeds as it completes safety track inspections. It told commuters to expect delays of up to 20 minutes systemwide.

“While 911 received an increase in calls from people who felt shaking, there have been no reports of injuries in San Francisco at this time, the city’s department of emergency management posted on X. The department said it has not received any damage reports.

San Francisco’s mayor, Dan Lurie, posted online about the quake, saying: “First responders are assessing any impact to our city, and we will give an update later today.”

“Things were shaking in our newsroom,” posted Dave Clark, a news anchor for KTVU-TV. “It caught everyone off guard.”

News stations reported that people as far south as Salinas, about 100 miles (160km) from Berkeley, felt it.