At least six Chinese banks have raised investment thresholds for their gold savings accounts, in an attempt to warn retail investors of potential risks amid a price rally and growing demand for the safe-haven asset.

Starting Friday, the Agricultural Bank of China Ltd. increased the minimum investment to 550 yuan ($76) from 500 yuan for one of its gold deposit products, according to a March 22 notice. The adjustment comes less than three months after the bank last raised the subscription threshold in early January.