LOS ANGELES (AP) — Two computer hackers were charged with sending false shooting and bomb threats to hundreds of schools and other institutions in the U.S. and Britain, federal prosecutors said Tuesday.

The men are members of Apophis Squad, a worldwide collective of hackers intent on using the internet to "sow chaos," the Department of Justice said in Los Angeles.

Timothy Vaughn of Winston-Salem, North Carolina, was arrested this week by the FBI. The 20-year-old used the online handles "WantedbyFeds" and "Hacker_R_US," according to the indictment.

George Duke-Cohan, 19, of Hertfordshire, United Kingdom, is currently serving a prison sentence in Britain for a hoax threat targeting an airliner. His internet usernames included "DigitalCrimes," court papers show.

It wasn't immediately known if the defendants have attorneys who could comment on the felony charges that include making threats to injure in interstate commerce and making interstate threats involving explosives.

The indictment alleges the Apophis Squad made false threats and engaged in "swatting," in which a phony report is made to trigger deployment of emergency response teams.

The hackers made false threats of shootings and bombings last year that were intended "to cause fear of imminent danger and did cause the closure of hundreds of schools on two continents on multiple occasions," the indictment said. One phony threat targeted Los Angeles International Airport.

Members of Apophis Squad used "spoofed" email addresses to make it appear some threats had been sent by innocent parties, including the mayor of London, according to court papers.

They also are accused of launching denial-of-service attacks, in which a hacker disables a computer network by flooding it with data, including ab attack that took down the website of a California motorsports company for three days.

Duke-Cohan is accused in the indictment of calling the FBI field office in Omaha, Nebraska, discussing the deployment of deadly pathogens in the building, and threatening to rape and kill the wife of an employee who answered the phone.