This year London Fire Brigade (LFB) has dealt with 17 incidents, compared with seven in the same period last year.

Often there is widespread disruption as 24-hour cordons are put in place as the cylinders are cooled.

LFB said so far in 2007, 2,000 people had been moved from homes and offices because of these "hazard zones".

Dangers and costs

Research by LFB revealed that in the whole of 2005 officers dealt with 15 incidents and a further 16 incidents in 2006.

At the scene of these fires, initially, a 200 metre hazard zone is put in place while the cylinders are cooled for 24 hours, before the area is reopened.

In March the Eurostar line had to be shut down for 24 hours after a fire in a railway arch.

Val Shawcross, chairwoman of the London Fire and Emergency Planning Authority, which manages LFB, said: "These figures show the real dangers and costs of acetylene cylinder incidents across London.

"We need the help of local councils in working with local business to ensure that acetylene is only used when it is really needed, and that it is always used and stored safely."