TERROR

Authorities say terrorism investigation leads to 6 arrests in Minnesota, California

  • United States Attorney Andrew Luger, right, and FBI special agent Richard Thornton explain the criminal complaint charging six Minnesota men with terrorism at a news conference in Minneapolis, Monday April 20, 2015. The six, whom authorities described as friends who met secretly to plan their travels, are accused of conspiracy to provide material support and attempting to provide material support to a foreign terrorist organization. The complaint says the men planned to reach Syria by flying to nearby countries from Minneapolis, San Diego or New York City, and lied to federal investigators when they were stopped. (AP Photo/Andy Clayton-King)

    United States Attorney Andrew Luger, right, and FBI special agent Richard Thornton explain the criminal complaint charging six Minnesota men with terrorism at a news conference in Minneapolis, Monday April 20, 2015. The six, whom authorities described as friends who met secretly to plan their travels, are accused of conspiracy to provide material support and attempting to provide material support to a foreign terrorist organization. The complaint says the men planned to reach Syria by flying to nearby countries from Minneapolis, San Diego or New York City, and lied to federal investigators when they were stopped. (AP Photo/Andy Clayton-King)  (The Associated Press)

  • FBI special agent Richard Thornton explains the criminal complaint charging six Minnesota men with terrorism at a news conference in Minneapolis, Monday April 20, 2015. The six, whom authorities described as friends who met secretly to plan their travels, are accused of conspiracy to provide material support and attempting to provide material support to a foreign terrorist organization. The complaint says the men planned to reach Syria by flying to nearby countries from Minneapolis, San Diego or New York City, and lied to federal investigators when they were stopped. (AP Photo/Andy Clayton-King)

    FBI special agent Richard Thornton explains the criminal complaint charging six Minnesota men with terrorism at a news conference in Minneapolis, Monday April 20, 2015. The six, whom authorities described as friends who met secretly to plan their travels, are accused of conspiracy to provide material support and attempting to provide material support to a foreign terrorist organization. The complaint says the men planned to reach Syria by flying to nearby countries from Minneapolis, San Diego or New York City, and lied to federal investigators when they were stopped. (AP Photo/Andy Clayton-King)  (The Associated Press)

  • FBI special agent Richard Thornton, right, with United States Attorney Andrew Luger explain the criminal complaint charging six Minnesota men with terrorism at a news conference in Minneapolis, Monday April 20, 2015. The six, whom authorities described as friends who met secretly to plan their travels, are accused of conspiracy to provide material support and attempting to provide material support to a foreign terrorist organization. The complaint says the men planned to reach Syria by flying to nearby countries from Minneapolis, San Diego or New York City, and lied to federal investigators when they were stopped. (AP Photo/Andy Clayton-King)

    FBI special agent Richard Thornton, right, with United States Attorney Andrew Luger explain the criminal complaint charging six Minnesota men with terrorism at a news conference in Minneapolis, Monday April 20, 2015. The six, whom authorities described as friends who met secretly to plan their travels, are accused of conspiracy to provide material support and attempting to provide material support to a foreign terrorist organization. The complaint says the men planned to reach Syria by flying to nearby countries from Minneapolis, San Diego or New York City, and lied to federal investigators when they were stopped. (AP Photo/Andy Clayton-King)  (The Associated Press)

Federal authorities say six people have been arrested in Minnesota and California in connection with a terrorism investigation.

A spokesman for the Minnesota U.S. Attorney's Office says the arrests were made Sunday in Minneapolis and San Diego but there is no threat to public safety.

Spokesman Ben Petok did not give details about the charges but said they are related to an investigation in Minnesota in which authorities have been tracking youths who have traveled or tried to travel to Syria to fight with militants, including the Islamic State group.

An FBI spokesman said six people were arrested.

The U.S. Attorney's Office and the FBI planned a news conference Monday to announce details. The announcement will include details of a "joint terrorism task force operation."