Three people connected to one of the San Bernardino terrorists have been arrested in a marriage fraud conspiracy.
The US Attorney's Office said those arrested at two southern California locations include the brother and sister-in-law of gunman Syed Rizwan Farook.
The third person arrested is the wife of Enrique Marquez Jr, a friend of Farook who has been charged over his alleged role in aiding last year's violence.
The two women arrested are Russian immigrants.
Prosecutors said the three participated in a marriage fraud conspiracy that involved lying under oath to obtain immigration benefits.
FBI spokeswoman Laura Eimiller confirmed the warrants were served in the cities of Corona and Ontario
The December 2 shootings carried out by Farook and his wife Tashfeen Malik were the deadliest terror strike on US soil since 9/11.
The couple opened fire at an annual training event of Farook's San Bernardino County co-workers.
The 14 people killed and 22 wounded were mainly his colleagues.
Both attackers died in a gun battle with police.