Police are attending a shooting at a social services facility in California.
The San Bernardino Fire Department tweeted that it was responding to a "20 victim shooting incident" and it was working to clear the scene.
It is still a "very active scene" and police are trying to secure the building, said a spokeswoman from the San Bernardino Police Department.
There may be up to three gunmen she said, and they were heavily armed and possibly wearing body armour.
She did not confirm the number of victims.
A local reporter tweeted that people are being evacuated from the Inland Regional Center, a non-profit medical and health organisation.
Depends how you describe a loon as its a centre for vulnerable people (social services)and is more likely to be a dysfunctional loon or two who're doing this.If the early reports are true of not the usual American loon with a gun and grudge but three gunmen it could prove to be another attack
Shirley American gun laws should be relaxed to allow US citizens to fight back against these crazy gun men.
The attack was on a christmas party for autistics, police securing Malls in the area.