Before the three were stopped, they had gone as far as Germany. Two of the three, who are all between 15 and 17, are sisters.
A member of their family refused to make a comment at their metro Denver home, but denied the allegations that law enforcement alleges about the two sisters.
The three returned to Denver late Sunday night after they had been reported missing by their parents on Friday along with their passports and cash in the amount of $2,000.
The parents of the three girls alerted the FBI. The federal law enforcement agency then made sure that authorities stopped the teens when they were arriving at the Frankfurt airport in Germany on Friday.
Investigators from the federal government suspect the three girls might have become radicalized and had intentions of going through Turkey into Syria to join Islamic State. However, they did not face charges on Tuesday.
In September, an attorney for another teen in Colorado told a judge that Shannon Connelly his client regretted attempting to join the radical group this past April.
Connelly, who is a converted Muslim and goes by the name Halima, was planning to relocate to Syria to join a man she had met online. However, authorities arrested her at the Denver airport.
Her attorney said Halima is completely aware that her arrest at the airport might have saved her life.
Teens are being manipulated said authorities by a social media campaign carried out by IS.
The campaign has high quality productions that appear to be trailers for an action movie in Hollywood.
It sends out tweets that have links to different videos that show fighter from Islamic State giving candy to children in Syria.
Many of the videos feature people who are speaking English with an American sounding accent.
The director of the FBI James Comey said tracking the public relation campaign of the IS and the people that are impacted by it is a top priority of the FBI as this time.