A man suspected of killing 11 people in a synagogue in Pittsburgh has been charged with murder - in what is believed to be the worst anti-Semitic attack in recent US history.
Robert Bowers, 46, is accused of opening fire at the Tree of Life synagogue during its Sabbath service.
He faces 29 criminal counts, including use of a firearm to commit murder.
Federal prosecutors say they will also file hate crime charges, and the suspect could face the death penalty.
President Donald Trump described the attack as a "wicked act of mass murder".
Six people - including four police officers - were injured in Saturday's attack.
The suspect was also wounded in a shootout with police.
Hundreds of people - from the neighbourhood and also all across Pittsburgh - later gathered for an interfaith vigil for the victims of the attack in the synagogue in Squirrel Hill.
Sophia Levin, a local resident and one of the organisers, told the BBC people wanted to be "together, not alone", and the vigil would help heal the city.
President Trump said he would visit Pittsburgh soon. He also ordered US flags at government buildings to be flown at half-mast until 31 October.
What are the charges?
The 29 charges were announced in a statement issued by the US Attorney's Office of the Western District of Pennsylvania:
- Eleven counts of obstruction of exercise of religious beliefs resulting in death
- Eleven counts of use of a firearm to commit murder during and in relation to a crime of violence
- Four counts of obstruction of exercise of religious beliefs resulting in bodily injury to a public safety officer
- Three counts of use and discharge of a firearm during and in relation to a crime of violence
How did the shooting unfold?
On Saturday morning, worshippers had gathered at the synagogue for a baby naming ceremony during the Sabbath.
Squirrel Hill has one of the largest Jewish populations in Pennsylvania and this would have been the synagogue's busiest day of the week.
Police said they received first calls about an active shooter at 09:54 local time (13:54 GMT), and sent officers to the scene a minute later.
According to reports, Mr Bowers, a white male, entered the building during the morning service armed with an assault rifle and three handguns.
The gunman had already shot dead 11 people and was leaving the synagogue after about 20 minutes when he encountered Swat officers and exchanged fire with them, FBI agent Robert Jones said.
The attacker then moved back into the building to try to hide from the police.
He surrendered after a shootout, and is now being treated in hospital for what has been described as multiple gunshot wounds.
The crime scene was "horrific", Pittsburgh's Public Safety Director Wendell Hissrich told reporters. "One of the worst I've seen, and I've [worked] on some plane crashes. It's very bad."
Mr Hissrich said no children were among the casualties.
What do we know about the gunman?
US media said he had shouted "All Jews must die" as he carried out the attack.
Social media posts by someone with the name Robert Bowers were also reported to be full of anti-Semitic comments.
FBI special agent Bob Jones told a press conference that Mr Bowers did not appear to be known to authorities prior to the attack.
He said that any motive remains unknown but that authorities believe he was acting alone.
'Grief and hurt'
Gary O'Donoghue, BBC News, Pittsburgh
In the dwindling light, and with the cold autumn rain falling, hundreds gathered in front of the 6th Presbyterian church just a few streets away from the Tree of Life Synagogue.
Holding their candles, they sang the Jewish prayer of healing.
The elders in the community had wanted to wait a day before holding the vigil, but the young people said no - they wanted an immediate chance to share their grief and voice their hurt.
Fifteen-year-old Sophia Levin declared that she was a different Jew today to the one she was yesterday. Anti-Semitism, she said, had been something she thought happened elsewhere and in earlier times; but now she knew it was right here, right now.
Some of these young people have been involved in the student gun control movement that sprang up after the Parkland shooting earlier this year.
One of them, Rebecca Glickman, told the crowd that gun control was needed now more than ever.
She told me that an anti-Semite with a gun is more dangerous than an anti-Semite without a gun, so that's a good place to start.
What has been President Trump's reaction?
He called the shooting a "terrible, terrible thing".
"To see this happen again and again, for so many years, it's just a shame," he told reporters.
He described the gunman as a "maniac" and suggested the US should "stiffen up our laws of the death penalty".
"These people should pay the ultimate price. This has to stop," he said.
Mr Trump added that the incident had "little to do" with US gun laws. "If they had protection inside, maybe it could have been a different situation."
Former US President Barack Obama voiced a different position on the ongoing gun law debate, tweeting: "We have to stop making it so easy for those who want to harm the innocent to get their hands on a gun."
What about other reaction?
Pennsylvania Governor Tom Wolf said in a statement that the incident was an "absolute tragedy" and that such acts of violence could not be accepted as "normal".
The president of the Jewish Federation of Greater Pittsburgh, Jeff Finkelstein, said his "heart goes out to all these families".
"Now I'm just sad. This should not be happening. Period. It should not be happening in a synagogue. It should not be happening in our neighbourhood here in Squirrel Hill," he said.
Jonathan Greenblatt, the head of the Anti-Defamation League (ADL), a Jewish non-governmental organisation that fights anti-Semitism, said he was "devastated".
"We believe this is the deadliest attack on the Jewish community in the history of the United States," he said in a statement.
World leaders also condemned the attack, including Israeli Prime Minister Benjamin Netanyahu who said he was "heartbroken and appalled", and German Chancellor Angela Merkel who said: "We all have to stand up against anti-Semitism, everywhere."
Extra police officers have been deployed at synagogues and Jewish centres across the US after the attack.
The BBC's Dan Johnson in Washington says the shootings come at a tense time in the US, after a week in which mail bombs were sent to critics of Mr Trump, ahead of crucial mid-term elections next month.