Police activity at San Francisco International Airport on Thursday shut down its BART station.
San Francisco police were responding to an incident in front of the BART station around 8 a.m. local time, the airport said.
Officers engaged a "threatening individual" in front of the station, KNTV reported. It was unknown whether the individual was armed, according to multiple local reports.
The airport said passengers in the area may be directed around the activity.
At 8:40 a.m., SFBART tweeted that the station was reopening.
Further details were not immediately available.