San Bernardino shooter Syed Rizwan Farook had contact with people from at least two terror organizations overseas, including the Nusra Front in Syria and al-Shabab in Somalia, a federal law enforcement official said Friday.

The revelations came as the FBI formally announced they were investigating the shooting spree as an act of terrorism.

Farook and his wife, Tashfeen Malik, died in a police shootout on Wednesday several hours after bursting into a holiday potluck for the San Bernardino County health department and killing 14 people.

As the investigation expands, the law enforcement source said, agents are trying to learn more about the couple’s contacts here and overseas, “especially those in Pakistan” where Farook visited and Malik was born. One key question, said the official, “is if they had any weapons or terror training in Pakistan.” The sources described "some kind" of contact between Farook and people from the Nusra Front and al-Shababa. It's unclear what type of contact or with whom....