"It has unfortunately been noted that some people write words and sentences on bankotes ," the bank said in a statement carried by the state-run news agency IRNA.
"It has unfortunately been noted that some people write words and sentences on bankotes ," the bank said in a statement carried by the state-run news agency IRNA.
"Those who have such banknotes should exchange them in banks across Iran and people must avoid writing on banknotes," it added.
Since the beginning of Iranian people's uprising, anti-regime slogans such as "Down with Dictator," "Death to Khamenei" have appeared on banknotes. And in many cases the picture of Khomeini carried on the higher denomination banknotes has been crossed out.