The Siberian Times, an English-language newspaper, published pictures of two new giant holes discovered by reindeer herders, one located in the Yamal and the other in the Taymyr peninsula, both above the Arctic circle.
The paper said that theories of their origin range from meteorites or stray missiles to aliens or an underground gas explosion. The report could not be confirmed independently.
Russian state TV reported earlier this month that a giant hole had appeared in the gas-rich Yamal peninsula where temperatures plummet below -50 degrees Celsius (-58 degrees Fahrenheit) and the sun barely rises in winter.
A Russian scientific expedition arrived at the site to inspect the first crater, nicknamed the "Yamal black hole", earlier this month, according to a recent report by state-run Vesti.ru website.