A burst water main has blocked lines between Stratford and Tottenham Hale, meaning trains through the stations may be cancelled until further notice.
Trains between the stations via Lea Bridge are being disrupted due to the water pipe flooding the rail lines at Lea Bridge.
Thames Water have been made aware and are dealing with the incident.
Earlier on Tuesday, Overground trains could not travel to or from Stratford after a lorry collided with a bridge in north London.
The accident happened between Camden Road and Caledonian Road & Barnsbury stations at around 10.10am on Tuesday.
It comes after more than 24 hours of major disruption to one of the UK’s busiest lines serving London Waterloo, with the route between Woking and Surbiton affected until about 10am on Tuesday.
