A person has been hit by a train between Hove and Worthing this afternoon (Saturday).
Services between these stations are severely disrupted after the incident, which reportedly happened at Southwick at about midday.
Emergency services are at the scene.
Southern said at about 2.30pm that lines have reopened, but disruption is still expected.
It said in a statement on Twitter, “Lines have reopened between Hove and Worthing after a person was sadly struck by a train earlier.
“We are working to run as many trains as we can and some replacement buses but major disruption continues.
“Brighton and Hove and Stagecoach buses will still accept our tickets.”