At least six men were arrested in California and Minnesota by the FBI on Sunday after a joint terrorism task force investigation into youths who traveled or tried to travel to Syria to join ISIS . A spokesman for the US Attorney 's Office said the arrests were made in Minneapolis and San Diego but there is no threat to public safety . Spokesman Ben Petok did not give details about the charges and said more information would be released on Monday . Scroll down for video . Arrests were made Sunday in Minnesota and California after an investigation into youths traveling to join ISIS in Iraq and Syria ( file picture ) Three men who were arrested in Minneapolis ( above ) were already known to authorities , according to reports . Cross country : A Somali mother said one son was arrested in Minneapolis and the other was arrested in San Diego ( above ) At least three men who were arrested in the Twin Cities were already known to authorities , according to KMSP . The three men were stopped from boarding a plane to Istanbul with Hamza Ahmed , 19 , at JFK Airport after riding on a Greyhound bus with him from Minneapolis to New York in November . Ahmed was indicted for lying to the FBI during a terrorism investigation , conspiring to provide material support to the ISIS and attempting to provide material support in February . He has pleaded not guilty . No public charges were filed against his companions and little information was released about them . An FBI affidavit said they are all between the ages of 19 and 20 and live in the Twin Cities . A Somali woman said one of her sons was arrested at her house in Minneapolis around noon and the other was arrested in San Diego , according to MPR News . She said she did n't know why more than 12 FBI agents and police officers searched her house and confiscated a tablet . The FBI made at least six arrests in Minneapolis and San Diego following a joint terrorism task force operation . The US Attorney 's Office and the FBI will hold a news conference Monday to announce details about the joint terrorism task force operation . An FBI spokesman in San Diego referred questions to a spokesman in Minneapolis , who said Sunday he could not comment . Authorities say a handful of Minnesota residents have traveled to Syria to fight with militants within the last year . At least one Minnesotan has died while fighting for the Islamic State . Since 2007 , more than 22 young Somali men have also traveled from Minnesota to Somalia to join the terrorist group al-Shabab . Four Minnesotans have already been charged in connection with supporting terror groups in Syria , including ISIS .
Arrests made headlines after investigations into youths traveling to join ISIS . Details are scarce but authorities believe there is no threat to public safety . Three men arrested in the Twin Cities were already known to authorities . Reportedly rode bus to NYC with Hamza ##b and tried flying to jail . years - old charged with lying to FBI and trying to provide support to ISIS . The US prosecutor 's Office and the FBI will hold a news conference Monday .