Gold remained above $4,500 an ounce on Thursday after rising more than 4% in the previous session, supported by a sharp retreat in US Treasury yields. The US Treasury Department said it would more than double repurchases of 10-, 20- and 30-year debt in the next few months after the 30-year yield reached its highest level since 2007 earlier this week. Lower yields reduce the opportunity cost of holding gold, which pays no coupon. Federal Reserve minutes from the July meeting showed that some policymakers supported raising interest rates this year to guard against stronger inflation later. Uncertainty in the Middle East, with the US and Iran at a stalemate, also kept inflation risks in focus.