The US college gunman who killed at least nine people before being fatally shot in a stand-off with police was originally from the UK, it was reported.
Chris Harper-Mercer was said to have been born in England before moving to the States as a young boy, according to reports in America.
The 26-year-old, whose social media profiles featured content supporting the IRA, apparently demanded to know his victims' religious beliefs before opening fire at Umpqua Community College in Roseburg, Oregon.
Authorities, who initially refused to name the gunman, shed no light on his motive and said they were investigating. Several people remain injured in hospital.
It is the 45th school shooting in the US this year.
Witnesses described the moment the gunman stormed the school.
Kortney Moore, 18, said she was in a writing class when a shot came through the window and hit the teacher in the head.
The gunman then entered the Snyder Hall classroom and told people to get on the floor, she told the Roseburg News-Review newspaper. He told people to stand up and state their religion before opening fire.
The gunfire, shortly after 10.30am local time, sparked panic as students ran for safety and police and ambulances rushed to the scene.
Hannah Miles, 19, said she was in her writing class when her teacher got a call from security saying the school was in lockdown. She heard gunshots from a neighbouring classroom.
She said that huddled together in the locked classroom, the students and teacher heard footsteps outside and a man's voice call out to them: "Come on out, come on out." They remained quiet and did not open the door.
Police soon arrived and, after students were convinced that it was indeed officers, they opened the door.
"It was like a huge burden had been lifted," she said. "A huge sigh of relief that we were going to be OK."
Douglas County Sheriff John Hanlin said at least two officers acted heroically in the shoot-out, but it was not clear if the gunman was killed by authorities or whether he took his own life.
At a news conference, a visibly angry Mr Hanlin said he would not name the shooter.
He said: "I will not name the shooter. I will not give him the credit he probably sought prior to this horrific and cowardly act."
"It's been a terrible day. Certainly this is a huge shock to our community."
Bronte Hart, a neighbour in Harper-Mercer's community of Winchester, said he would "sit by himself in the dark in the balcony with this little light".
She said a woman she believed to be the gunman's mother also lived upstairs and was "crying her eyes out" on Thursday.
Carmen Nesnick, Harper-Mercer's step-sister, said he was born in the United Kingdom and travelled to the United States as a young boy.
She added: "I'm actually still shaking and my mom is in there crying. I don't know what to do."