The Forth Road Bridge was closed for seven hours due to a police incident.
The A9000 was shut in both directions at 9pm on Friday.
The nature of the incident is not known.
In a post to X, formerly known as Twitter, Stagecoach East Scotland said: “Due to emergency services closing the Forth Road Bridge in both directions, all services are having to divert via the Queensferry Crossing.”
Traffic Scotland confirmed that the bridge reopened at 4.05am.
Police Scotland has been contacted for comment.