The incident happened on the line between Southampton Central and Bournemouth and all lines are blocked, South Western Rail (SWR) Help have reported.
Train services running through these stations may be cancelled, delayed or revised.
The incident is expected to cause disruptions until 10am, meaning commuters who are using this line could have see their journeys affected.
SWR have arranged the following replacement bus services:
- There will be three coaches at Bournemouth station (operated by Bluebird coaches). Two will run fast to Southampton Central and one will call at all stops. These will be in operation from 8am. - Coaches will run from Southampton Central departing at 8am. - Further coaches have been requested to run between these stations.
Tickets will also be accepted on the following services:
- GWR services from Southampton Central to Weymouth (via Westbury) and Westbury to Reading. - GTR services between Portsmouth/Southampton and London Victoria.
On its website, SWR said: ‘For further information or onward travel advice please speak to a member of staff or use a station help point. ‘We are very sorry for any delay that this may cause to your journey.’