The incidents happened on the Picadilly Line through Islington

London Underground chiefs said sorry for technical problems which caused chaos for rush-hour Tube commuters, this morning.

Signal failures at Baker Street caused severe delays on the Metropolitan line, Circle line and the Hammersmith and City line.

By midday a normal service had been resumed, except for the Hammersmith and City line which had minor delays.

London Underground Network Operations Director, Nigel Holness, said: “At 7.06am a signal failure at Baker Street resulted in delays on the Metropolitan, Hammersmith and City and Circle lines.

“Engineers fixed the problem by 7.53am and we are working to restore a good service as soon as possible.

“We would like to apologise to customers who had their journeys disrupted this morning.”