San Bernardino: San Bernardino shooter Syed Farook had contact with people from at least two militant organisations overseas, including the al Qaeda-affiliated Nusra Front in Syria, the Los Angeles Times reported on Friday, citing a federal law enforcement official.
The official described "some kind" of contact between Farook and people from the Nusra Front and the radical al Shabaab group in Somalia, the Times reported.
It is unclear what type of contact or with whom, the newspaper said.
On Friday, the FBI said the mass shooting in California is being investigated as "an act of terrorism" amid reports the female assailant had pledged allegiance to the Islamic State group on Facebook.
The developments in the probe come two days after 14 people were killed and 21 others wounded at a year-end office party in San Bernardino -- the deadliest mass shooting in the United States since the Newtown school massacre in 2012.
US-born Syed Farook, 28, and his 27-year-old Pakistani wife Tashfeen Malik were killed in a firefight with police hours after the attack, leaving investigators to comb through their belongings to try to determine a motive.
FBI director James Comey said the probe so far had shown that the couple were radicalised and inspired by "foreign terrorist organisations," but were not part of a larger group or cell.
Bowdich said investigators were scrutinising evidence seized at the couple`s home and elsewhere to determine what prompted the carnage.
Meanwhile, one of Farook`s colleagues said he was convinced Malik had radicalised her husband.
(With Agency inputs)