A hole under a railway line has caused travel misery for commuters for the second time in less than three weeks.
Lines running into London Bridge station were closed "as a safety measure" and services cancelled after the discovery of the 30cm hole at Forest Hill in the south east of the capital.
It comes after another hole opened up in the same area on July 18, also shutting down lines into London Bridge and causing major delays.
Rail operator Southern warned customers it expected disruption in the area until 6pm on Thursday.
A Network Rail spokesman said: "At around 3am this morning we were alerted to a small hole, around 30cm across, which appeared on the railway in the Forest Hill area.
"Our engineers are on site assessing the damage and carrying out repairs. We offer our apologies to passengers travelling to London through the area this morning as their journey will be disrupted."
The hole saw Southern Services towards London Bridge unable to stop at Norwood Junction, Anerley, Penge West, Sydenham, Forest Hill, Honor Oak Park, Brockley, and New Cross Gate. London Overground services were also affected between New Cross Gate and Crystal Palace / West Croydon.
Thameslink trains from Brighton into London were only able to run as far as Gatwick Airport.
A Southern spokesman said: "Some services have been cancelled. Others may be delayed or diverted away from London Bridge. Disruption is expected until 6pm."