The FBI said on Tuesday it had thwarted a potential threat ahead of the Ultimate Fighting Championship mixed martial arts event in Washington last weekend and has multiple people in custody.

Fox News Digital cited unidentified sources as saying the alleged plot involved using explosive-laden drones to hit buildings near the event.

"On June 10, FBI and our law enforcement partners became aware of a potential threat to the UFC America 250 event in Washington, D.C. involving individuals outside of the National Capital Region," FBI Director Kash Patel said in a statement posted on X.

Patel did not specify how many people were in custody after the multistate operation on the alleged planned attacks.

Five people were in custody and 23 were identified as part of a network of plotters, Fox News Digital reported.

President Donald Trump, at the Group of Seven summit in Evian, France, said he had not heard about the planned attack.

Vice President JD Vance said authorities were trying to look at the underground networks that would drive such violence.

"Twenty-three people do not get to the point where they're going to commit a mass terror incident in Washington, D.C. without some serious funding, without some serious coordination," Vance said in a Fox News interview.

"That's not a few guys doing crazy stuff, that is a coordinated planned terrorist plot," he told Fox News' "Fox & Friends" program.