All services from Swiss Cottage station were halted after an emergency alert sounded.
One person tweeted the trains were halted because of the “smell of smoke”.
The disruption has caused severe delays on the Jubilee line.
Music fans on their way to see Justin Bieber tonight at the 02 Arena tweeted their frustration at the delays.
One fan @zoebowx93 wrote: “Typical that the jubilee line has to be suspended #cantbelateforbieber”
According to the Underground line”s Twitter page, trains have been suspended between Waterloo and Finchley Road as emergency services investigate.
London Fire Brigade have sent crews.
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