(ETH) – A swarm of drones reportedly flew over a restricted area at Palo Verde Nuclear Power Plant on two separate occasions last September. And now a new report from Forbes is revelating that according to documents obtained under the Freedom of Information Act (FOIA) 24 nuclear sites were apparently the target of at least 57 drone incursions from a timeline of 2015 to 2019 – and Palo Verde was also targeted again in December, despite new security measures.

According to these documents that were obtained from the U.S. Nuclear Regulatory Commission these were apparently commercial drones. Back in Septemeber, a swarm of five or six large drones flew over the Unit 3 nuclear reactor at Palo Verde in Arizona for nearly eighty minutes, which is considered to be a length of time in which they were carrying out a thorough survey of the site.

The documents also revealed a similar incident that took place at Limerick Nuclear Generating Station in Pennsylvania. These documents were obtained from the U.S. Nuclear Regulatory Commission by Douglas D. Johnson who also did a followup on these incidents Johnson sent a follow-up request to get more details and was met with a list of fifty-seven security incidents (SIDs) involving drones,

running from December 2014 to October 2019 and the report also showed that the NRC has no idea who the perpetrators are or what they intended, and has given up on finding nearly 85% of all the drone incidents that took place.

These latest reports reveal that the scale and number of intrusions are a clear indication that this is not a localized issue, but raise the possibility that drone overflights could be carried out by a large, coordinated organization. Forbes went on to report:

“While most of the sites were nuclear reactors, there were also three drone incursions over spent nuclear fuel storage sites, including Trojan in Oregon and Rancho Seco in California where radioactive waste is stored in steel canisters inside giant concrete casks.” This latest report is very disturbing and raises the question of how well secured our nuclear facilities and even water supplies are across the country.