British Jews were reassured that they face no specific threat after a plot to bomb trans-Atlantic flights from London was thwarted.The terrorism alert in Britain was raised Thursday to critical, the highest level, after police uncovered a plan they said aimed to create �mass murder on an unimaginable scale� by detonating explosives on up to 10 aircraft. However, police informed community leaders that they had no intelligence suggesting that U.K. Jews were targeted, though the situation was still being monitored.Arrests connected to the plot were made in Birmingham and Thames Valley as well as in Hackney, London, close to the fervently Orthodox Stamford Hill neighborhood.