Iran's rial falls to a new low as the central bank announces up to $2 billion in support.

Reuters reported that the dollar traded at about 2.688 million to 2.695 million rials on two free-market tracking sites, compared with 2.632 million on Friday. Iranian state television said state banks began selling up to $2 billion to support the currency.

The rial has lost more than half its value over the past year, while Reuters put inflation above 70%. A central-bank adviser described the latest decline as temporary and partly driven by pessimistic external forecasts.