Two additional suspects made their initial court appearances Monday in connection with the alleged conspiracy to attack the Ultimate Fighting Championship event held at the White House on June 14, the Justice Department said.

Jordan Rincker, 28, of St. Joseph, Mo., appeared in a Kansas City federal court, and William Lee Spartacus Falkner appeared before a judge in Tacoma, Wash. Both face one count of conspiracy to commit murder, according to a Justice Department release.

The arrests bring to seven the number of people charged in what federal authorities have described as a 23-person conspiracy. The alleged plot targeted the Freedom 250 event, a celebration of the United States’ 250th anniversary and President Donald Trump’s 80th birthday.

Court documents outline a scheme that prosecutors said involved attacking the north side of the event with explosive-carrying drones, forcing attendees to evacuate to the south side, where snipers would open fire on fleeing crowds. Federal authorities said they learned of the alleged plot from the parents of Tycen Proper, 19, who alerted police to their son’s purchase of weapons and online activities. Proper was among the initial five suspects arrested and charged last week.

Prosecutors alleged that FBI agents reviewing Proper’s communications identified Falkner as a co-conspirator. According to the criminal complaint, Falkner indicated he had experience manufacturing and piloting drones and discussed loading them with explosives.

“I can fly 40+ drones at the same time at the same target,” Falkner is alleged to have said in online communications reproduced in the complaint.

Prosecutors said the communications included logistics discussions about potential flight costs, 3D printing, and shipping of drones.

According to court documents, authorities identified Rincker through information provided by Abraham Alvarez, 31, who was arrested and charged last week. Prosecutors alleged that Rincker met Alvarez in person two days before the planned attack and accepted $1,200 from him. Rincker then allegedly sent $100 via CashApp to another previously charged suspect, Bryan Roa, 24, to pay for his drive from California to Washington, D.C.

The FBI said it executed search warrants at Rincker’s residence and storage unit, uncovering weapons and related paraphernalia including a gas mask with cartridge, night vision goggles, ballistic plates, and a 3D printer.

Prosecutors also alleged that Rincker gave a 12-gauge shotgun to Alvarez during an in-person meeting in Omaha.

No attack occurred at the UFC event, which Trump and other Cabinet members attended. Asked about the thwarted plot a day after the event, Trump told reporters, “The attack that I watched were the fighters,” drawing laughter. “They were as good a fights as I’ve ever seen. The best.”