The New York Times has issued a strong call for more gun control in the US, in the wake of this week's mass shooting in California.
'The Gun Epidemic' editorial on the front page of today's newspaper - which is also available online - marks the first time since 1920 that the paper has run a front page editorial.
The editorial board of the newspaper writes that it is "a moral outrage and a national disgrace that people can legally purchase weapons designed specifically to kill with brutal speed and efficiency".
They add that it isn't necessary to debate the wording of the US Constitution's Second Amendment, saying "no right is unlimited and immune from reasonable regulation".
They specifically call for the outlawing of specific types of weapons and ammunition, such as the 'slightly modified combat rifles' used in this week's mass shooting in San Bernardino, California by a married couple that left 14 dead and 21 dead.
Image: New York Times
It comes after the FBI says it is investigating the shooting as an "act of terrorism", with the wife having pledged allegiance to a leader of Islamic State (IS).
Barack Obama, in a sombre weekly television address, pledged to get to the bottom of what had prompted the husband and wife to launch their attack, but said a wider debate was needed.
"We know that the killers in San Bernardino used military style assault weapons, weapons of war, to kill as many people as they could," he said.
"It is another tragic reminder that here in America, it is way too easy for dangerous people to get their hands on guns.
"For example, right now, people on the no-fly list can walk into a store and buy a gun. That is insane.
"If you are too dangerous to board a plane, you are too dangerous by definition to buy a gun.
"I am calling on Congress to close this loophole now."
The no-fly list is created and maintained by the United States government's Terrorist Screening Center (TSC).
It was created by the administration of George W Bush in the wake of the 9/11 attacks in New York and is estimated to contain at least 50,000 names.
Both US-born Syed Farook and his wife, Tashfeen Malik, died in a shootout with police hours after Wednesday's attack on a holiday party at a social services centre.
"Based on the information and the facts as we know them, we are now investigating these horrific acts as an act of terrorism," David Bowdich, assistant director of the FBI's Los Angeles office, said at a news conference.
He pointed, in particular, to the discovery of two crushed cell phones left by the couple in a trash can near their rented townhouse.
Mr Bowdich said it was hoped data retrieved from the phones and other electronic devices seized in the investigation would lead to a motive for the attack.
The couple had two assault-style rifles, two semi-automatic handguns, 6,100 rounds of ammunition and 12 pipe bombs in their home or with them when they were killed.
Mr Bowdich said they may have been planning another attack.
He said neither Farook, 28, or Malik, was on the intelligence radar, even though they had "telephonic connections" with the subjects of FBI investigations.
FBI Director James Comey said on Friday there is no current indication the couple were part of a larger organised network, group or cell.
Aamaq, a news agency affiliated with IS, has said the pair were "supporters" of the extremist group, although it stopped short of claiming responsibility for the attack.
According to the Los Angeles Times, the husband had contact with people from at least two militant organisations overseas, including the al Qaeda-affiliated Nusra Front in Syria.
