By Brad Ryan in Washington DC

The grand jury returned the indictments about 9pm local time, after sitting for hours after the court’s usual 5pm closure.

Donald Trump already faces federal charges over his alleged efforts to have Joe Biden's election win overturned. He pleaded not guilty to those charges in a Washington court earlier this month.

He’s also pleaded not guilty to offences relating to the handling of classified documents in Florida, and allegedly falsified business records in New York.

Trump, and some of his senior staff, have been under investigation in Georgia’s Fulton County for more than two years.

The district attorney, Fani Willis, launched an investigation shortly after the media published audio of a phone call between Trump and Georgia’s secretary of state.

In that call, Trump told the secretary of state, Brad Raffensperger: "Look, all I want to do is this: I just want to find 11,780 votes."

That was the number needed to flip Georgia back in Trump’s favour.

The former president, who polling indicates is an easy frontrunner to win the Republican presidential nomination for 2024, has been attacking the Georgia investigation on social media today.

In one post, he wrote:

"WOULD SOMEONE PLEASE TELL THE FULTON COUNTY GRAND JURY THAT I DID NOT TAMPER WITH THE ELECTION. THE PEOPLE THAT TAMPERED WITH IT WERE THE ONES THAT RIGGED IT, AND SADLY, PHONEY FANI WILLIS, WHO HAS SHOCKINGLY ALLOWED ATLANTA TO BECOME ONE OF THE MOST DANGEROUS CITIES ANYWHERE IN THE WORLD, HAS NO INTEREST IN SEEING THE MASSIVE AMOUNT OF EVIDENCE AVAILABLE, OR FINDING OUT WHO THESE PEOPLE THAT COMMITTED THIS CRIME ARE. SHE ONLY WANTS TO 'GET TRUMP.'"

Trump is now expected to be called to face court for an arraignment hearing in coming days.

Security in downtown Atlanta has been at an increased level for weeks in preparation for the case.

Crowd-control barricades have been put up on the street outside the court, and there’s been a heavy police presence around the building.

People with recent court hearings were asked to dial in via Zoom instead of attending in person, and local media reported court staff were being directed to work from home for much of August.