Spot gold rose to $391.50/392.00 per troy ounce by 1448 GMT, up from $391.00/391.50 at Friday's close in New York.
The United States declared a "high" level threat alert for financial institutions in New York and Washington on Sunday after intelligence warnings of an al Qaeda attack. The news knocked the dollar off multi-week highs against the euro, lifting the appeal of gold for non-US investors.
Gold markets will take their next cue from the Institute for Supply Management's (ISM) manufacturing index, due at 1400 GMT. Analysts expect the figures to show modest growth in the US manufacturing sector.
The figures are the last major data before the Federal Open Market Committee meets on August 10, when it is widely expected to hike rates by a quarter-point to 1.50 percent. Rises in US interest rates are seen as supportive for the dollar.
Fresh long positions in the gold market were also underpinning prices. After two weeks of aggressive long liquidation, analysts said selling pressure was abating.
"The latest (Commitments of Traders) COTR report shows a further reduction of long positions. This might help gold to rally at least in the short term," said analyst Alexander Zumpfe at Dresdner Kleinwort Wasserstein.
The Commitments of Traders data records how many people have made contracts to buy or sell gold.
Zumpfe said a close above $392.30 would be necessary to maintain the developing upward momentum. Spot silver was quoted at $6.63/6.66, up from Friday's close at $6.52/6.55.
Platinum firmed to $825.00/830.00, against $817.50/822.50 on Friday. Palladium traded at $215.00/220.00, from $214.50/220.50 in the US market.