The United States Federal Bureau of Investigation said on Friday that a mass shooting at an office party in San Bernardino, east of Los Angeles, California, which killed 14 people was being investigated as an “act of terrorism”.
"Based on the information and the facts as we know them, we are now investigating these horrific acts as an act of terrorism," David Bowdich, assistant director of the Federal Bureau of Investigation's Los Angeles office, told reporters.
The statement came after two US government sources reported that a woman, Tashfeen Malik, who joined her husband in killing 14 people in the shooting pledged allegiance to the leader of DAESH terrorist group on Facebook.
Malik posted her support under an account with a different name and then deleted it before the incident, the officials told US media.
Bowdich said that he had seen the posted Facebook message and said that "we're looking into it."
Malik, 27, a native of Pakistan, and her US-born husband Syed Rizwan Farook, 28, both died about four hours later in a gunbattle with police. The attack was the deadliest mass shooting that the US has witnessed in three years with 14 dead and 21 wounded.
The couple had 12 pipe bombs, weapons and thousands of rounds of ammunition at their home, a police raid on the premises revealed, following the massacre.
Farook had worked as an inspector for the San Bernardino County Department of Environment Health, the agency whose holiday party he and Malik attacked on Wednesday.
Bowdich also said that the FBI was also investigating crushed mobile phones found near the shooting scene and had established that there were "telephonic connections" between the couple and other people of interest in FBI probes.
US government sources said that even if the attack may have been inspired by DAESH, there was no evidence that it was directed by the terrorist group.
On Friday, after the couple’s landlord in the town Redlands opened their house to media, influx of reporters and camera crews entered surveying the scene.
US government source stated that the FBI’s search in the house came up with no evidence to suggest that they had been working with any foreign group.