The National Science Foundation (NSF) has issued a two-week pause on travel to Antarctica after more than 70 COVID-19 cases were detected at its research outpost on the continent.

In a statement released on Friday, NSF said it would be moving to reduce the “density” of the population at the McMurdo research station in Antarctica, where nearly 1,000 researchers are deployed.

“The U.S. National Science Foundation’s priority is always the health and safety of our communities while ensuring the overall science mission can be achieved. Following the confirmation of more than 70 positive cases at McMurdo station, NSF is reviewing the existing protocols implemented at the start of the season in September to reduce the transmission rates,” the agency said.

In a second update over the weekend, the NSF said it would be “implementing a pause on all travel to [Antarctica] for the next two weeks, effective immediately, while we reassess the situation.”

This pause excludes essential travel needed for health and safety reasons.

The NSF said 10 percent of the deployed population at Antarctica is currently testing positive for COVID-19. Due to this infection rate, those at McMurdo has been advised to wear KN-95 masks at all times.

An NSF spokesperson told the Wall Street Journal that symptoms reported among those at McMurdo have been mild. So far, 98 cases have been confirmed from among the 993 people who are stationed there and 64 cases are currently active.