The Secret Service announcement about the alleged NYC plot came as President Donald Trump is set to speak at the U.N. General Assembly meeting.

The Secret Service said it has foiled a telecommunications network of tens of thousands of devices that could have been used to wipe out cell networks in New York City, all while world leaders gathered there for the United Nations General Assembly.

An investigation was launched after “multiple telecommunications-related imminent threats” were made toward senior U.S. government officials in the spring, Matt McCool, special agent in charge of the Secret Service field office in New York, said.

“This network had the potential to disable cell phone towers and essentially shut down the cellular network in New York City,” McCool said.

Investigators found more than 300 co-located SIM servers and 100,000 SIM cards in the New York tri-state area, concentrated within 35 miles of the General Assembly meeting. It’s not clear if the devices were intended to disrupt the meeting and communications of world leaders, but the Secret Service said it moved quickly to dismantle the network given the timing and proximity of the threat. The network could have disrupted emergency communications, McCool added.

The Secret Service made the announcement as President Donald Trump was set to address the General Assembly for the first time during his second presidential term on Sept. 23.

The devices allowed for anonymous, encrypted communication, which allowed criminal organizations to operate undetected, McCool said.

A team that included Homeland Security, the Department of Justice, the Office of the Director of National Intelligence and the New York Police Department worked together in the investigation, McCool said. Investigators are now working to analyze data from the equivalent of 100,000 cell phones.

“Early analysis indicates cellular communications between foreign actors and individuals that are known to federal law enforcement,” McCool said.

The devices no longer pose a threat, he said. The Secret Service did not announce any arrests in connection with the network.