Updated | 'As many as 10 to 20 people' shot in San Bernardino shooting

San Bernardino Country Sheriff’s Department tweets unit responding to reports of 20 victims in shooting incident

The San Bernardino Police Department has confirmed an active shooter in San Bernardino, California after a unit responded to reports of 20 victims following a shootout.

The number of suspects varies between one to three.

San Bernardino County Sheriff’s Deputy Olivia Bozek said shots were heard around 11 a.m. (Pacific time) when authorities got the first 911 call. She said no additional gunshots were heard since authorities secured the building's perimeter.

“They’re still trying to evacuate the building,” Bozek said. “Nobody is in custody.”

Bozek said there are one to three suspects. She said as many as 10 to 20 people were shot.

Video from the scene showed people lying on the ground, and police helping to support others who were wounded, CNBC reports.

The attack was believed to have taken place in a cluster of office buildings that include the offices of Inland Regional Services, which offers services to individuals with developmental disabilities. Dozens of people fled from the building and were being herded by the police across Waterman, onto the golf course of the San Bernardino Golf Club.