Passengers travelling on several major rail lines across South East England have been told to expect cancellations and delays to services throughout Wednesday because of "multiple incidents".
Southern, Thameslink and Gatwick Express - all part of the Govia Thameslink Railway (GTR) franchise - issued a "do not travel" alert this morning, which has now been lifted.
But services face continuing disruption after the incidents, which included a train derailment near a depot in Selhurst, southeast London.
A separate signal failure between London Blackfriars and Norwood Junction has compounded problems for rail operators, including causing disruption to London Overground's Windrush Line.
The derailed Southern service had prevented other trains from leaving a nearby depot, but there had been "no confirmed injuries".
Images from the scene showed one of the carriages skewed across the track, but the entire train had managed to remain upright. Engineers were also spotted working at the site.
National Rail has issued a warning to people travelling to Gatwick Airport and Luton Airport Parkway to allow at least an extra 60 minutes for their journey, because of disruption to the network.
Southern and Thameslink both advised passengers to allow at least an extra 45 minutes.
Operators confirmed that any tickets bought for services that have been disrupted are being accepted on other routes at no additional cost, and some bus services south of London.
Earlier GTR and Network Rail both apologised for the impact, which is expected to disrupt journeys for the rest of the day.
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In a joint statement, they said: "A fault with the signalling system between Norwood Junction and London Bridge, along with the derailment of an empty train that wasn't in passenger service at Selhurst depot, means our services are disrupted.
"We're working to resolve these issues as quickly as possible."
GTR, which also includes operator Great Northern, is the UK's largest railway franchise in terms of the number of passengers carried.
Some 18% of train journeys in the UK are made on GTR services, according to the company.
Elsewhere, a fault with the signalling system between Crewe and Sandbach means trains have to run at a reduced speed. National Rail said services may be cancelled, delayed by up to 40 minutes, revised or diverted.
(c) Sky News 2026: Train cancellations and delays hit routes across South East England after multiple incidents
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