PITTSBURG — A gunman who killed 11 worshippers at a Pittsburgh synagogue, in the deadliest antisemitic attack in US history acted with "malice and hatred", a court has heard.

Prosecutors described how the attacker barged into the synagogue in 2018 and shot every worshipper he could find.

His "malice and hate can only be proven in the broken bodies" of the victims, said the lead prosecutor.

If convicted, Robert Bowers, 50, could get the death penalty.

Eight men and three women -- ranging in age from 54 to 97 -- died in the attack inside the Tree of Life synagogue on 27 October 2018.

The gunman, who has pleaded not guilty, is on trial for more than 60 federal charges including obstruction of free exercise of religion resulting in death and hate crimes resulting in death.

The defendant's lawyers had offered to plead guilty on all counts, in exchange for a sentence of life in prison instead of the death penalty, but federal prosecutors rejected such a deal.

Most families of those killed have voiced support for the death penalty.

"The defendant had moved methodically through the synagogue to find the Jews he hated and kill them," Soo Song, the lead prosecutor, said in her opening statement on Tuesday.

The court heard audio of the 911 call one of the victims made to emergency dispatcher Shannon Basa-Sabol, who was the first witness in the trial.

She received Bernice Simon's desperate call from inside the Tree of Life synagogue.

"Tree of Life, we're being attacked... We're being attacked!" Ms Simon said on the phone.

"My husband's shot, oh dear God, my husband's bleeding, he's shot in the back."

Ms Simon and her husband, Sylvan, were both killed.

Some survivors cried in court.

Tree of Life rabbi and attack survivor Jeffrey Myers testified how he prayed while on the line with a police dispatcher as the attack unfolded.

"I thought about the history of my people, how we've been persecuted and hunted and slaughtered for centuries, and how all of them must have felt the moments before their death, and what did they do," Myers told the court.

Three congregations -- Dor Hadash, New Light and the Tree of Life -- shared the synagogue.

Judy Clarke, the defense lawyer, acknowledged to jurors on Tuesday that there was no disputing her client carried out the attack, but she questioned whether he had acted out of hatred.

She argued that the death penalty sentencing option was unconstitutional because she said the former truck driver suffers from serious mental illnesses, including schizophrenia.

She also said he was "a socially awkward man who didn't have many friends" and that he had "misguided intent" and "irrational thoughts".

The 12 jurors were told that the defendant frequently posted antisemitic slurs online, on sites like Gab, and prosecutors said he shouted "all Jews must die" during the attack.

Investigators said he was carrying multiple weapons on him, including a semi-automatic rifle.

Police shot the gunman three times before subduing him. Five of the injured included police officers who responded to the scene.

The trial in the US District Court in Pittsburgh in western Pennsylvania is expected to last several weeks. — BBC