A total of 270 people died in the Lockerbie bombing on 21 December 1988

The US has announced charges against a Libyan suspected of making the bomb that blew up Pan Am Flight 103 over Lockerbie, Scotland, in 1988.

Abu Agila Mohammad Masud has been charged with terrorism-related crimes, Attorney General William Barr said on Monday, 32 years since the attack.

The blast on the Boeing 747 killed 270, including 190 American citizens.

Prosecutors will seek the extradition of Mr Masud to stand trial in the US.

The attack on the London to New York flight remains the deadliest terrorist incident ever to have taken place in the UK, and the second deadliest air attack in US history.

Eleven people on the ground in Scotland were also killed. The victims included 35 study abroad US students who were returning home for Christmas.

The new charges bring Mr Barr’s role in this lengthy terrorism investigation full circle, as he held the same post when charges were first announced against two Libyan suspects in 1991.

Back then, serving under President George H W Bush, Mr Barr tasked his criminal division head Robert Mueller to look into the bombing. Mr Mueller is now best known for leading the inquiry into Russian meddling in the 2016 presidential election.

Both Mr Barr and Mr Mueller have taken part in remembrance events with families over the years.

Mr Barr said he was “pleased to announce that the United States has filed criminal charges against the third conspirator Abu Agila Mohammad Masud for his role in the bombing”.

“Let there be no mistake, no amount of time or distance will stop the United States and our Scottish partners in pursuing justice in this case.”

Mr Barr said the “breakthrough” that led to Monday’s charges came when authorities learned he was being held in Libya. Mr Barr said Libyan authorities provided a copy of their interview with Mr Masud to US officials.

He said Mr Masud allegedly built the bomb and worked with two other co-conspirators. He said late Libyan leader Muammar Gaddafi had also personally thanked Mr Masud “for the successful attack on the United States”.

“At long last this man responsible for killing Americans and many others will be subject to justice for his crimes,” Mr Barr said.

The attorney general added that he is “optimistic” that the Libyan government will hand Mr Masud over.