Woman in San Bernardino Shootings Tried to Contact Militants: Source

Tashfeen Malik, left, and Syed Farook are pictured passing through Chicago's O'Hare International Airport in this July 27, 2014 handout photo obtained by Reuters December 8. Reuters

Shooter Tashfeen Malik tried unsuccessfully to contact multiple Islamic militant groups in the months before last week's San Bernardino, California, attack, a U.S. government source said on Thursday.

Two U.S. government sources said the militant groups likely ignored Malik's approaches because they have recently become extremely wary of responding to outsiders who they do not know or who have not been introduced to them.