An image of the new notes has appeared in a Japanese newspaper
People in North Korea have been setting fire to old notes of the national currency, the won, a report says.
The Daily NK website said people had been burning piles of old bills in anger over the government's reported redenomination of the currency.
The move is said to have knocked two zeros off the nominal value of each banknote, although Pyongyang has not confirmed the action.
An image of the new notes has appeared in the Japan-based Choson Sinbo paper.
North Korea's official media has kept quiet over any reform of the currency, but newspapers based in South Korea and Japan have said that the government informed citizens and foreign embassies of the move on Monday.
If true, a 1,000 won note ($7; £4.20) will now be worth just 10 won.
Initially, residents were only allowed to exchange 100,000 won per household for the new currency, according to media reports.
But the government later increased the amount, allowing each family member to trade an additional 50,000 old won for new ones.
Old notes were being burned at two separate locations in the eastern coastal city of Hamhung, Seoul-based the Daily NK said, citing an unidentified resident.