The US Department of Justice has again indicted former FBI Director James Comey.

On Tuesday, Acting Attorney General Todd Blanche announced that Comey had been charged with threatening the life of US President Donald Trump.

Comey, an outspoken critic of Trump, has also been charged with making an interstate threat to kill the president, according to Blanche.

In response, the former FBI director said on Tuesday that he was "still innocent" and unafraid after being indicted by US authorities.

"I'm still innocent, I'm still not afraid, and I still believe in the independent federal judiciary, so let's go," Comey said in a video statement.

What do we know so far? 

Earlier on Tuesday, CNN reported that the indictment was linked to an Instagram post from Comey last May, which showed shells on a beach forming the numbers "86 47." Donald Trump is the 47th US president, with Republican critics saying the post is a reference to killing or taking out Trump. 

It would be the second time the Justice Department under Trump has indicted Comey. 

Comey was indicted last September for making a false statement to Congress and on one charge of obstruction. Comey had pleaded not guilty.

The earlier charges had been dropped in November after a judge ruled that the appointment of the prosecutor in the case, Lindsey Halligan, was unlawful.

Comey was fired by Trump in 2017

Comey served as FBI director from 2013 to 2017 and is a frequent critic of Trump.

He was fired by Trump in 2017 over his handling of Hillary Clinton's emails, but Democrats at the time said the dismissal was connected to the FBI's investigation into the 2016 Trump presidential campaign's ties with Russia.  

The Justice Department under the second Trump administration has been under pressure by the president to prosecute his political enemies. Acting Attorney General Todd Blanche previously served as Trump's personal attorney.  

Edited by: Srinivas Mazumdaru, Dmytro Hubenko