The report came after a Cuadrilla site in Lancashire had to stop test fracking in 2011 after two small earthquakes were felt at the surface.

BBC: Shale will free US from oil imports, says ex-BP boss

Cuadrilla suspended shale gas test drilling in June 2011, following two small earthquakes near Blackpool.

BBC: Fracking firm Cuadrilla plans new well at St Annes site

But in the UK, the use of fracking was halted in 2011 after some minor earthquakes near Blackpool, Lancashire, were attributed to test wells being drilled by the energy company Cuadrilla.

BBC: Company to submit fracking plans for land near Bath