Signs China’s economic slowdown is deepening and weak growth in Europe and the U.S. reported on Friday further damaged the outlook for the global economy, sending stocks and commodity prices reeling. China’s factory sector shrank at its fastest rate in almost 6-1/2-years in August, a private survey showed, pushing investors who fear China’s sagging economy will translate into slower global economic growth to take refuge in gold and bonds. World markets had already been on edge after China’s surprise devaluation of the yuan last week and a 33 percent fall in its stock markets since mid-year.