Two US men accused of trying to join a Somali terror group have been held in custody following their first court appearance.
Mohamed Alessa, 20, and Carlos Almonte, 24, from New Jersey, were arrested on Saturday before they could board flights to Egypt, then Somalia.
They are charged with conspiring to kill, maim and kidnap persons outside the US by joining the al-Shabab group.
The pair face a bail hearing on Thursday.
Prosecutors said the two men possessed only knives but were dangerous despite their apparent lack of sophistication.
"Sophistication is not a measure of danger," US Attorney Paul Fishman said. "Their intentions were described pretty clearly. They were watching certain videos and interested in what certain people were saying and advocating."
Al-Shabab was designated a terrorist group by the US in 2008.
Prosecutors said the men, arrested on Saturday at New York's JFK International Airport, prepared for the alleged attacks on US troops by lifting weights, playing violent video games and watching terrorist videos online.
In their initial court appearance on Monday in Newark, New Jersey, the two men spoke only to confirm they understood the charges against them.
Mr Alessa, of Palestinian descent, was born in the United States. Almonte is a naturalized US citizen who was born in the Dominican Republic.
Prosecutors said the men drew inspiration from Anwar al-Awlaki, a radical US-born cleric linked to other terror plots.
The arrests follow two failed attacks in the US in recent months: an attempted car bombing in Times Square last month and the attempted Christmas Day bombing of a Detroit-bound airliner.