Rail services on a train line on Surrey have been suspended “until further notice” due to a fault with the signalling system.
Southern Rail and South Western Railway (SWR) have said trains cannot run between Epsom and Dorking until further notice after disruption began on Saturday afternoon.
Buses are being bought in to replace trains, with journeys expected to take 30 minutes longer than advertised, the operators said.
No trains are able to serve Box Hill & Westhumble station, while Dorking, Leatherhead, Ashtead and Epsom will have an extremely reduced service throughout the day.