Barack Obama
US President Barack Obama says the US will not be terrorised Reuters

President Barack Obama has admitted it was "entirely possible" the mass shootings in San Bernardino was "an act of terror" at the hands of Islamic State (Isis) terrorists. Syed Rizwan Farook, 28, and his wife, Tashfeen Malik, 27, killed 14 people and injured 21 at an office Christmas party before being shot dead themselves in a police shoot-out.

Isis (Daesh) has reportedly hailed the murders, claiming the couple, via its al-Bayan radio that they had been their "followers".

Speaking during his weekly address on Saturday, the US president said: "It is entirely possible that these two attackers were radicalised to commit this act of terror. And if so, it would underscore a threat we've been focused on for years — the danger of people succumbing to violent extremist ideologies."

Obama called on government, police and faith leaders to work together to stop more people "falling victim to these hateful ideologies".

Farook was said to be "living the American dream" and had "everything to be happy" – working as an environmental health specialist for the San Bernardino County Department of Public Health.

Members of their family are reportedly shocked that they could have carried out such an atrocity. According to the BBC, a lawyer representing the family knew that Farook owned two handguns and two rifles, but were unaware of the massive arsenal found at their home nearby the shooting.

Farook's sister, Saira Khan, told CBS News: "I can never imagine my brother or my sister-in-law doing something like this, especially because they were happily married. They had a beautiful six-month-old daughter."

Around the time of the killings Malik had posted on Facebook in support of IS leader Abu Bakr al-Baghdadi.

Farook and Malik's mass shooting has the highest number of fatalities of any in the US since the Connecticut school shooting in 2012, in which killed 27 people. According to the website Shooting Tracker, there have been 353 mass shootings in the US so far in 2015.