US prosecutors warned that the Islamic State group is continuing "intense" recruitment efforts among the youth of Minneapolis, after a teenager pleaded guilty Wednesday to trying to join the extremists in Syria.
In New York, another young man, one of four who were accused in June of trying to join IS, pleaded guilty to terror charges Wednesday.
Hanad Mustofe Musse, 19, is among nine Minneapolis-area youths charged in April with plotting to join IS. All but one of them were arrested before they could reach Syria and Musse is the second to plead guilty.
Musse had made multiple attempts to travel to Syria, even trying to obtain a false passport after he and a friend were stopped by federal agents from boarding a flight to Greece in November, the plea agreement said.
"Criminal prosecution was the best remaining option to stop him and potentially save his life," said Andrew Luger, US attorney for the district of Minnesota.
Teens in the Minneapolis area "continue to be the targets of an intense recruiting campaign" by the Islamic State, he said in a statement.
"Fighting back is the shared responsibility of a wide cross-section of Minnesotans, parents, religious leaders, teachers, community leaders and law enforcement," he added. "We must continue to work together to end the cycle of recruiting."
The Minneapolis area -- home to a large Somali immigrant community -- has also been a target of recruiting by Somalia's Al-Qaeda-affiliated Shebab rebels.
At least 20 young men who disappeared from the "Twin Cities" of Minneapolis and St. Paul between 2007 and 2009 are believed to have joined Shebab. Several were killed there, including two who carried out suicide bombings.
Samuel Rahamin Topaz, 21, is one of four young people from the New York area who were arrested in June for planning to join IS.
Musse and Topaz face up to 20 years in prison after pleading guilty to conspiring to provide material support to a designated terrorist organization.
"The crimes Samuel Topaz admitted today threatened the safety of Americans here and abroad," said Paul Fishman, US attorney for the district of New Jersey.
"Our efforts to cut off the flow of fighters and resources to known terrorist organizations will not stop with his guilty plea," Fishman said in a separate statement.