Elfgeeh tried to recruit others to fight with Islamic State militants in Syria, police say
A court in the US has formally charged a man with planning to assist the Islamic State militant group and attempting to murder US soldiers.
Mufid A Elfgeeh, 30, a naturalised citizen from Yemen, was arrested in May after an undercover operation.
Mr Elfgeeh, from Rochester, New York, tried to buy two handguns from an FBI informant, court documents said.
He planned to kill Shia Muslims and American military personnel returning from the Middle East.
As this case shows, our agents and prosecutors are using all the investigative tools at our disposal to break up these plots before individuals can put their plans into action,” said Attorney General Eric Holder in a statement.
Court documents say that Mr Elfgeeh was placed under close surveillance more than a year ago when he started posting tweets in support of Islamic State (IS) militants.
He urged people to donate money to the militants, suggesting people should give a third of their salary
He then tried to persuade the undercover operative and two others to go to Syria “and fight on behalf ” of Islamic State militants.
Prosecutors said Mr Elgeeh wanted to buy handguns to carry out shootings, saying he might target US military personnel returning from the Middle East and Shia Muslims living in the Rochester area.
As part of the plan to kill soldiers, Elfgeeh purchased two handguns equipped with firearm silencers and ammunition from a confidential source they said.
The FBI disabled the guns before their informant gave them to Mr Elfgeeh.