(ANSA-AFP) - LONDON, MAR 20 - European gas prices soared as much as 35 percent on Thursday as fresh strikes hit energy infrastructure in the Middle East, including Qatar's main gas facility. The Dutch TTF natural gas contract, considered the European benchmark, jumped to 74 euros, before paring gains slightly. Two waves of Iranian strikes caused "extensive damage" at Ras Laffan in Qatar, the world's largest liquefied natural gas hub, raising fresh concerns over energy supplies. (ANSA-AFP).