Media playback is unsupported on your device Media caption The BBC's David Shukman explains how fracking works

Fracking for shale gas has begun for the first time in the UK since it was linked with earthquakes in 2011. Image caption Protesters were sitting in the road outside the site, leading to its closure

Campaigner Bob Dennett, who failed to stop the work from beginning in the High Court, said: "They have sacrificed Lancashire to the gods of greed." Image copyright PA Image caption Protester Anne Power in Preston New Road site said she was "so angry" fracking has started

Lee Petts, chairman of Lancashire For Shale pro fracking group, said he was "really pleased" that fracking had finally started after a "long journey". The protesters have said their fight has just "got serious" as the controversial process is due to get underway in Lancashire.
Fracking for shale gas begins in the United Kingdom for the first time since it was suspended in 2011 after being linked to a series of earthquakes. Cuadrilla Resources say they will spend at least three months fracking two horizontal wells in Lancashire.