'Couple radicalised before online dating'

The couple behind the San Bernardino attack that killed 14 people were radicalised before they started dating, the director of the FBI has said.

James Comey said Tashfeen Malik and husband Syed Farook spoke of jihad and martyrdom during conversations on an online dating service in late 2013. Malik moved to the US in July 2014 on a visa designed for fiances, and married Farook - US native - a month later.

The FBI believes the duo were inspired by foreign terrorist organisations, but said the investigation is ongoing.

Separately, a US government source familiar with the investigation yesterday said Farook may have contemplated an attack on a US target as early as 2011 or 2012.

Last week's massacre was the deadliest terrorist attack in the US since 9/11.

The couple were both killed in a shoot-out with police hours after the attack.

Speaking during a Senate hearing in Washington, Comey characterised the couple as "homegrown violent extremists," and said that precise nature of the foreign influence is still under investigation.

Earlier this week, another FBI official said that there was no evidence uncovered so far to suggest the attack was plotted overseas.

The BBC's Jane O'Brien in Washington says the revelation is significant, as it contradicts earlier suggestions that Malik may have radicalised her husband.