FBI investigates California shooting as act of terrorism

The mass shooting at a Southern California office party is being treated as an act of terrorism – but the FBI said there was no indication the husband and wife who killed 14 people were part of a larger plot or members of an Islamist cell.

Update 10:18am

A radio station, apparently associated with so-called Islamic State, claims that two followers of the extremist group carried out the deadly shootings in California.