The Federal Bureau of Investigation in the United States announced on Friday that it is investigating the mass shooting at a California social service agency’s office party as an act of terrorism. FBI Director James Comey said the investigation so far has developed indications of the slain couple who killed 14 people in San Bernardino of being radicalised, and of potential inspiration by foreign terrorist organisations. However, he added there “is a lot of evidence that doesn’t quite make sense”. He also said there is no indication that the couple were part of a larger plot or members of a terror cell, reported AP.

The authorities also did not cite specific evidence that led them to the terrorism link. A US law enforcement official said that the woman, Tashfeen Malik, had under a Facebook alias pledged allegiance to the Islamic State militant group and its leader. The IS-affiliated news service Aamaq called Malik and her husband Syed Rizwan Farook supporters of their Islamist cause, but did not particularly claim responsibility for the attack. Malik and Farook died in a fierce gunfight with the police hours after the mass shooting on Wednesday.