Rail services between Havant and Chichester were affected due to 'urgent track repairs' this morning (Tuesday), Southern has said.
According to Southern, a problem at Southbourne station caused the disruption between the stations.
A Southern spokesman said: "Reports were received from a member of station staff that a track defect has occurred in the Southbourne area, blocking the line.
"Specialist engineers from Network Rail are currently onsite and have made a full assessment of the damage to the track."
Southern, which said disruption is expected until late this morning, confirmed all lines were reopened just before 11.30am.
However, it advised that services may still be subject to delay, alteration or cancellation until the end of the day as it 'works to return to a normal working service'.
Due to the repairs, Bognor Regis to Barnham shuttles were suspended, Littlehampton to Havant services were suspended, London to Southampton or Portsmouth services were diverted into either Littlehampton or Bognor Regis, and a special shuttle service was introduced between Barnham and Chichester.
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