The Iranian rial has lost more than half of its value in the past year. (EPA Images pic)

DUBAI: Iran's rial continued its decline on Saturday, as the central bank announced an injection of up to US$2 billion to support the currency while the economy faces US sanctions and a naval blockade.

The US dollar was sold for around 2.688 million rials, up from 2.632 million on Friday, according to free-market tracking website bon-bast.com, while alanchand.com reported 2.695 million rials per dollar.

State television said state banks began selling up to US$2 billion to support the currency, which has lost more than half of its value in the past year.

With an inflation rate of more than 70%, life is becoming ever tougher for ordinary citizens unable to afford basic necessities or rent ​as a US blockade cuts the state's financial lifeline -- oil exports.