Precious metals mostly increased on Monday trading session extending monthly gains amid speculation that metal supplies may be curbed by a decision of the European Union and the U.S. to put sanctions on Russia. Silver for settlement in May added 0.9% to $19.965 an ounce, platinum for delivery in July jumped 1.1% to $1,423.30 an ounce and palladium for June settlement climbed 0.8% to $779.80 an ounce.