Almost 5,000 people have been evacuated from offices near Liverpool Street after a suspected gas leak.
A huge cordon has been set up surrounding Old Broad Street in the City after reports of a gas leak.
London Fire Brigade said a six-inch gas main was ruptured at a six-storey office block.
Footage shows thousands of people filling the streets ahead of lunchtime after the evacuation order.
Office workers standing on the street reported being told not to smoke in the area.
Traffic alerts show that the A1211 Wormwood Street is closed in both directions between Bishopsgate (Liverpool Street) and London Wall.
The fire service said: ‘There is a ruptured six-inch gas main at a six-storey office block. A 200-metre cordon has been put in place and around 4700 people have been evacuated from nearby buildings.
‘Two fire engines from Dowgate and Shadwell fire stations are in attendance as well as a Fire Rescue Unit from Bethnal Green fire station.
‘The Brigade was first called at 1056 and crews remain on scene.’
Several bus routes have been disrupted and are on diversion, including route 21, 43, 100, 141 and 153.
Meanwhile, rail and Underground services at Liverpool Street station are unaffected.
Metro has contacted the emergency services for more information.
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