Cairo, Dec 5 (EFE).– The Islamic State said in an online bulletin Saturday that two of its supporters carried out this week’s attack in the Southern California city of San Bernardino that left 14 dead.

The extremist group said in a broadcast on its Al-Bayan radio station that “two supporters of the Islamic State” attacked the Inland Regional Center, a facility providing services for people suffering from developmental disabilities.

It said those supporters killed 14 people inside the facility and wounded more than 20 before dying in a shootout with police.

“May God accept them as martyrs,” the bulletin said.

The announcement came hours after the head of the FBI field office in Los Angeles, Assistant Director David Bowdich, said Wednesday’s slaughter in a conference room at the center was being investigated as an “act of terrorism.”

It also followed several media reports indicating that one of the perpetrators – 27-year-old Tashfeen Malik – had pledged allegiance to Islamic State leader Abu Bakr al-Baghdadi in a message posted on Facebook hours before she and her husband, 28-year-old Syed Farook, carried out the massacre.

The conference room where the attack occurred was being used by the San Bernardino County public health department, where Farook had worked as an inspector for five years, for its annual Christmas party.

President Barack Obama, for his part, acknowledged in his weekly address Saturday that the attackers may have become radicalized but vowed that the United States “will not be terrorized.”

He also used his address to reiterate his call for stricter gun laws.

“We know that the killers in San Bernardino used military-style assault weapons – weapons of war – to kill as many people as they could. It’s another tragic reminder that here in America it’s way too easy for dangerous people to get their hands on a gun,” Obama said.

The killers were in possession of more than 1,600 rounds of ammunition during the confrontation with police that resulted in their deaths, and authorities found another 4,500 rounds – including 2,500 for assault rifles – in their home, along with explosives.

The quantity of arms and ordnance discovered in the residence suggests the couple were planning more than one attack, Bowdich said.

The official said at a press conference Friday in San Bernardino that the FBI was aware of the Facebook post, but he stopped short of saying there was a link between the attack, which he said involved “extensive planning,” and the Islamic State. EFE