The US has charged Hamas leader Yahya Sinwar and several other prominent figures in the Palestinian group in connection with its deadly attack in Israel on 7 October last year,
BBC reports.
The justice department said it was indicting six Hamas members with seven charges, including the murder of dozens of US citizens, conspiracy to finance terrorism and use of weapons of mass destruction.
The criminal complaint covers decades of alleged attacks by Hamas, as well as last October's unprecedented assault.
It is the first step by US law enforcement to hold accountable the ringleaders of that attack, but has been seen by analysts as partly symbolic, not least because some of those named in the indictment are already dead.
Meanwhile, Sinwar is believed to be hiding in tunnels somewhere under Gaza.
In a video statement on Tuesday, US Attorney General Merrick Garland said the defendants were responsible for "financing and directing a decades-long campaign to murder American citizens and endanger the security of the United States".
The group also "led Hamas's efforts to destroy the state of Israel and murder civilians in support of that aim", Mr Garland said.
He highlighted the 7 October attack on Israel by Hamas, in which the group "murdered entire families" in "the deadliest massacre of Jews since the Holocaust".
Mr Garland said: "They murdered the elderly and they murdered young children. They weaponised sexual violence against women, including rape and genital mutilation."
The charges were filed in February, but were kept under wraps until Tuesday in case the US had the opportunity to arrest any of the accused, an unnamed justice department official told CBS News, the BBC's US partner.
The justice department's complaint states that at least 43 American citizens were killed on 7 October.
The reason for the timing of the US charges was not immediately clear, although the recent discovery in Gaza of the body of an Israeli-American hostage - and five others - might have given the move "extra impetus", one analyst told the BBC.
The charges themselves were partly about the US sending "a message" to Hamas and anyone working with the group, added Prof Yossi Mekelberg, an associate fellow of the UK think tank Chatham House.