Iranian hackers have infiltrated a number of key industries around the world over the past two years, according to cyber-security company Cylance. The hackers' targets include companies tied to energy, transportation and infrastructure, and the infiltration could lead to physical damage that would endanger the safety of the world’s population, the firm said.

Airports, airlines and hospitals have been targeted, according to Cylance. The hackers have also gained access to the private networks of universities as well as aerospace, energy, and telecommunications companies.

Dubbed “Operation Cleaver” by Cylance, the hackers' efforts have infiltrated companies throughout the U.S. as well as China, England, France, Germany, India, Israel and Saudi Arabia. Reuters reports that energy companies Calpine Corp., Saudi Aramco and Petroleos Mexicanos, as well as Qatar Airlines and Korean Air, have been hit.

"We believe that if the operation is left to continue unabated, it is only a matter of time before the team impacts the world’s physical safety," the California-based cyber-security company said in the report.

More than 50 organizations have been infiltrated by the hackers, Cylance claims. It also says that evidence proves the same organization breached the U.S. Navy in 2013. An Iranian ambassador claims that Cylance’s report was false.

"This is a baseless and unfounded allegation fabricated to tarnish the Iranian government image, particularly aimed at hampering current nuclear talks," Hamid Babaei, spokesman for Iran's mission to the United Nations, told Reuters.