A deadly strain of bird flu has been confirmed for the first time on the Antarctic continent, scientists say, posing a potential threat to the region’s vast penguin colonies, Reuters reports.

“This discovery demonstrates for the first time that a highly pathogenic bird flu virus has reached Antarctica, despite the distance and natural barriers that separate it from other continents,” Spain’s Superior Council for Scientific Research (CSIC) said on Sunday.

The presence of the virus was confirmed on Saturday in samples of dead skunk (Stercorarius maccormicki) birds that were found by Argentine scientists near the Antarctic base of Primavera, CSIC added.

The confirmed case on the Antarctic Peninsula, which follows cases on nearby islands, including among Papuan penguins, highlights the risk to colonies in the region from H5N1 bird flu, which has decimated bird populations around the world in recent months.

“The analysis conclusively showed that the birds were infected with the H5 subtype of avian influenza and that at least one of the dead birds had a highly pathogenic avian influenza virus,” CSIC said in a statement.

Argentina’s Antarctic Institute said Monday that the South American country was working with Spanish researchers to test samples of dead birds found earlier this year near an Argentine base that confirmed the presence of the virus.

Hundreds of thousands of penguins gather in tight colonies on the Antarctic continent and nearby islands, which could facilitate the easy spread of the deadly virus.

Data from the Scientific Committee on Antarctic Research also showed one case confirmed at the research base.