Commuters are facing disruption on train services to and from Cannon Street in the City, and Charing Cross, due to signalling problems between New Cross and Lewisham.
National Rail said services running through New Cross and Lewisham "may be delayed or revised". The disruption is expected to continue until 4.30pm.
"A signalling problem near to Lewisham means that two lines are currently closed in the area," said the rail operator.
"Trains to and from Charing Cross will be delayed or revised, and some Cannon Street services will also be delayed."
NEW: Delays between New Cross and Lewisham expected until 16:30 https://t.co/aT0cOwbuwu— National Rail (@nationalrailenq) March 28, 2017
Earlier disruption at Waterloo after a person was hit by a train at Feltham has come to an end after emergency services dealt with the accident.
The emergency services have dealt with the incident between Staines and #Feltham and trains are now running normally between the stations.— National Rail (@nationalrailenq) March 28, 2017