The Docklands Light Railway (DLR) has closed after a fire at an electrical substation in east London.
About 28,000 people have been left without power, and the Rotherhithe, Limehouse Link and Blackwall Tunnels have also been shut, while crews make the site on Castor Lane in Poplar safe.
About 1,600 people have been evacuated from buildings in the area, including students from a nearby college.
A 25m (82ft) cordon is in place and the fire's cause is not yet known.
The London Fire Brigade (LFB) was called just before 13:00 BST and six crews from Shoreditch, Bethnal Green, Shadwell and Plaistow fire stations responded.
UK Power Networks, which has a live map of power outages, confirmed the cuts for many areas and said they were working to fix the issue.
The brigade said the closures of the DLR, Blackwall Tunnel, Rotherhithe Tunnel and roads in the area are likely to continue to cause disruption into rush hour, and alternative routes should be found if possible.
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