A United Airlines flight from London to San Francisco was diverted to Edinburgh Airport after the pilot declared an onboard emergency. The aircraft landed in Edinburgh at approximately 4.40pm on Thursday, following the issuance of a 7700 squawk code, which indicates a general emergency. The flight had taken off from London at 2.05pm and was initially on course to cross the North Atlantic Ocean. However, it turned back and headed towards Edinburgh instead. Unconfirmed reports suggest that emergency services were on standby as the plane touched down in the Scottish capital. According to FlightRadar24, the flight was originally scheduled to arrive in San Francisco at 5pm on Friday, but it remains unclear when it will now reach its destination following the diversion. The specific details regarding the nature of the emergency have not yet been disclosed. The Scottish Fire and Rescue Service confirmed they were alerted to the incident at 4.11pm but were stood down upon their arrival at the airport. United Airlines has been contacted for further information, and Edinburgh Airport has also been approached for comment regarding the incident.