"We did not find anyone alive. There were no survivors. The plane is in multiple charred fragments. Everything is burnt and smashed to pieces," said local hospital director Ismael Ali, who participated in the rescue mission.
Ali said a witness had reported seeing a fireball crash into a field near his home, indicating a possible mid-air explosion.
The plane had earlier been reported missing on a flight between the southern cities of Neuquen and Comodoro Rivadavia, in Rio Negro province.
Horacio Farre, a spokesman for the private company Sol, which owned the plane, confirmed that there had been no survivors.
The company said the plane had taken off at 8:08 pm (0438 IST) and crashed around 45 minutes later, shortly after issuing a distress signal.
The passengers on the Saab 340 twin-engine aircraft included 18 adults, one minor and three crew members, the company said, adding that an investigation would be carried out to determine the cause of the crash.
Isabel Yahuar, the mayor of the nearby town of Los Menucos, said the recovery had been difficult as the plane crashed in a remote region in the foothills of the Andes.
"In the area of the accident there is no mobile phone signal," she told local television. "It's very cold and the conditions of the rescue were very difficult."
The crash came two days after a small plane crashed outside Sao Paulo in neighbouring Brazil, killing its four passengers.
