National Rail have said that the delays were caused after a person was hit by a train at Wimbledon this morning.
Although lines have reopened, there are still delays of up to 40 minutes
There are also aterations and cancellations to trains between London Waterloo and Staines as crew are out of place from earlier disruption.
As well as the delays, trains between London Waterloo and Salisbury / Exeter are currently starting from and terminating at Basingstoke.
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Thursday afternoon's weather for the east of the region
Thursday afternoon's weather for the west of the region