The widow of the gunman who killed 49 people at a gay nightclub in Florida last year has been arrested.
The New York Times reported Noor Salman was arrested at her home outside San Francisco.
Police killed her husband, Omar S Mateen, 29 after his shooting rampage at the Orlando club.
Ms Salman faces federal charges of obstructing justice and aiding and abetting the attempted provision of material support to a foreign terrorist organisation.
Fifty-three people were wounded in the 12 June rampage, which surpassed the 32 people killed in the 2007 massacre at Virginia Tech university.
At the time, US media reported that Ms Salman went with Mateen to buy ammunition and drove him to the Pulse nightclub on a previous occasion because he wanted to survey it.
However, she said she tried to talk her husband out of carrying out the attack, sources quoted by NBC News said.
Police interviewed Ms Salman, believing she may have been aware of her husband's plans.
She told the FBI her husband had become radicalised in the year leading up to the attack.
Ms Salman is expected to appear in a Californian court on Tuesday.
She moved to the San Francisco area after the attack.
At the time of the attack, US President Barack Obama said it was appropriate for the FBI to investigate the massacre as an act of terrorism.
NBC News reported that Mateen called emergency services before the three-hour attack and swore allegiance to the so-called Islamic State (IS) militant group.
The group later said - via its affiliated Amaq news agency - that an IS "fighter" had carried out the attack.
Mateen's father, Mir Seddique, told NBC News the incident had nothing to do with religion, and might have been triggered by the sight of a gay couple kissing in Miami.
The shooting prompted calls by some members of the US Congress for legislation to tighten control of weapons sales.
- BBC / Reuters