OAKLAND -- A man with a gun was arrested on a BART train at the 19th Street station Thursday morning, police said.

His name and age were not immediately released.

Authorities said an off-duty San Francisco police officer riding a San Francisco bound train saw the gun in the man's waistband about 10:30 and was able to notify BART police with a detailed description of the man.

When the train stopped at the 19th Street station in downtown Oakland. BART and Oakland police boarded the train and detained the man and recovered the gun.

Train service was delayed for at least 10 minutes.

Check back for updates.