A shooting at Los Angeles International Airport on Friday prompted the San Francisco Police Department to increase security at San Francisco International Airport, according to local police.
A police spokesman said the increased security is "in an abundance of caution."
Police said they were in contact with the FBI, which is the lead investigative unit in the LAX shooting, along with other law enforcement agencies.
A shooting also caused delays and cancellations of some flights to and from Bay Area airports, officials said.
Two Southwest Airlines flights from SFO to LAX have been canceled, and many flights from LAX to SFO are seeing delays of as much as two hours, airport spokesman Doug Yakel said.
The impact of the shooting will differ by airline, Yakel said.
Virgin America, for instance, operates from the terminal at LAX where the shooting appears to have occurred, he said.
"Our best advice is for passengers to check with their airlines for updated flight info," Yakel said.
At Oakland International Airport, some Southwest Airlines flights have also been canceled or delayed, while other airlines such as Delta appear to be mostly on time, airport spokesman Brian Kidd said.
Officials at Mineta San Jose International Airport were not immediately available for comment.
Bay City News contributed to this report.