California police have warned of an active shooter in the city of San Bernardino, saying they are responding to an incident with at least one gunman and "multiple victims".
The county sheriff and fire departments reported varying numbers of victims, with the sheriff tweeting "multiple victims" and the fire department saying that units have responded "to reports of a 20 victim shooting incident".
San Bernadino police confirmed there is a live situation underway and that is has an officer on the scene.
A spokesman would not give more details.
The Twitter account of the sheriff's department confirmed "one to three possible suspects".