Gatwick Airport train station has been evacuated due to overcrowding, the airport has said.
Passengers are currently unable to enter the station and trains travelling in both directions through the station were suspended.
Rail operator Southern, who operate a number of services at the West Sussex airport, said anyone travelling to the airport is being advised to delay their journey until later where possible.
It added that journeys may take up to two hours longer than usual and passengers are not recommended to travel on Monday if possible.
The majority of Southern, Thameslink and Gatwick Express services through the station were suspended, although lines have now re-opened and operators said they are working to restore services.
Ticket are being accepted on local bus routes and other train lines, including Southeastern and South Western Railway.
A spokesperson for Southern said Three Bridges station would be closed for the rest of Monday.
Disruption has been caused after a police incident on Monday morning between Gatwick Airport and Haywards Heath and a separate incident between St Albans City and Luton.
Services are expected to be affected until the end of Monday.
