The Bakerloo Tube line in London has been suspended after a tunnel 'obstruction', initially reported as a collapse.
The incident occurred between Embankment and Waterloo, RMT Union sources told LBC News.
TFL denied there had been a tunnel collapse:
The London Fire Brigade said they had attended an incident at the site after smoke was seen to issue from the tunnel at around 6.05am.
However, the LFB said by 7am it was no longer in attendance, and the incident "didn't appear to be anything".
Transport For London said on its website that "the Bakerloo line is suspended between PC and Elephant & Castle due to obstruction in tunnel at Embankment. Severe delays".
Details of the incident are not yet clear, and calls by the Huffington Post UK to TFL, the British Transport Police and the RMT Union have not been returned as of press time.
Maintenance workers on the Tube are currently on a 72-hour strike over pensions.