UPDATE: 5:56 a.m. EST -- U.S. Attorney General Loretta Lynch said Wednesday that authorities have no indication that the attackers, who opened fire at a social service center in San Bernardino, California last week, were part of a wider cell or that they planned more attacks, Reuters reported. The radicalization of Syed Rizwan Farook and his wife, Tashfeen Malik, seemed to have been going on for some time, Lynch reportedly said, while speaking to reporters in London.

"At this point in time we do not have an indication that these two people were part of a larger cell or group," she said, according to Reuters. "We do not have an indication that they were planning specific things beyond this attack although that information is still evolving.

"We are trying to learn everything we can about both of these individuals, as individuals and as a couple, to determine why they chose that location, that event, that particular place to vent their rage," Lynch said.

"We are essentially digging into their lives as far back as we can," Lynch further said, adding: "Our view is that the radicalization had been going on for some time, but it's really too early to tell at this point what was the genesis of it for either of them."

Original story:

The attackers in last week’s Southern California shootings may have left a bomb at a social service center in San Bernardino to kill police officers, the Los Angeles Times reported, citing a source familiar with the investigation. Authorities are reportedly trying to determine whether Syed Rizwan Farook and his wife, Tashfeen Malik, had plans of a deadlier massacre.

San Bernardino Police Chief Jarrod Burguan reportedly said that a device found at the Inland Regional Center, where Farook and Malik opened fire on Dec. 2 killing 14 people, consisted of three bundled pipe bombs and remote-controlled car parts. These items were reportedly hidden inside a canvas bag left behind by the couple.

The source, who spoke on the condition of anonymity, told the LA Times that bomb technicians said they do not believe the device would have detonated as the building's sprinkler system was set off during the shooting, and the water could have led the device to malfunction. The build of the device was similar to crude explosives often seen on al Qaeda's Inspire magazine, a newsletter known to be used by radicals to get bomb-making instructions.

Last week, reports surfaced that Farook may have had contact with people linked to at least two terrorist organizations.

A federal law enforcement official told the LA Times that authorities described “some kind” of contact between Farook and people from al Qaeda-affiliated Nusra Front in Syria and the al-Shabab group in Somalia. Authorities also said that Malik, a native of Pakistan who had been living in Saudi Arabia before she met Farook through an online dating site, had pledged allegiance to Islamic State group leader Abu Bakr al-Baghdadi on Facebook on the day of the attack.

The Islamic State group, or ISIS, praised the attackers in an online radio broadcast last week, saying that two of its followers carried out the massacre.

Several details about the lives of Farook and Malik have emerged since the shooting. The attacks gave rise to concerns as the two, who led quiet lives in a two-bedroom townhouse with their 6-month-old daughter and Farook's mother, did not come to the attention of law enforcement before the shootings.

David Bowdich, chief of the FBI's Los Angeles office, told reporters Tuesday that the agency was working to determine how and where the two were radicalized and who might have led them to those beliefs.

Investigators believe Malik was radicalized before meeting Farook, FBI spokeswoman Laura Eimiller said, according to the Associated Press.  Malik reportedly entered the U.S. in July 2014 on a fiancée visa.