London fire LIVE: Massive blaze causes chaos as 100 firefighters rush to scene

A huge fire has broken out in a set of major railway arches in London this morning (Friday, July 4). Commuters face lengthy delays due to the blaze under the London Underground Piccadilly line tracks in South Harrow.

It is believed a number of gas cylinders have also exploded. The London Fire Brigade were called at around 1.15am and a total of 100 firefighters are currently at the scene.

This is a live blog. Scroll down for updates.