An active shooter situation is currently taking place at a San Bernardino social services center, Inland Regional Center, home for mentally disabled persons. Three gunmen have fled the scene are are being sought in the situation which began at about 11:14 a.m. Pacific Time.

Witnesses report at least three suspects, seen wearing ski masks, vests and military-style attire. They may be wearing body armor. Witnesses said the shooters carried “long rifles,” which police believe to be AK-47s. FBI and Bureau of Alcohol, Tobacco and Firearms (ATF) responding. Officials are looking for a black GMC truck, possibly a Yukon.

There are multiple buildings in the complex. A woman who works at a building where the shootings occurred texted her father, “Shooting at my work. Shot people. In office waiting for cops to catch him. Prayer for us.”

SWAT teams are moving through the buildings to clear them. Police used a robot to detonate a “suspicious device.”

The facility provides services to over 30,200 people, and employs nearly 670. It is uncertain how many were present at the time the shooting occurred.

President Obama has been briefed on the situation and presidential candidates are responding via Twitter.