Image copyright Reuters/BBC Image caption Mohammed Abouajela Masud and Abdullah al-Senussi have been named as suspects

Families of some of the 270 people who died in the Lockerbie bombing have welcomed the naming of two new suspects.

US and Scottish prosecutors want to interview Mohammed Abouajela Masud and Abdullah al-Senussi over the atrocity.

Abdelbaset al-Megrahi is the only person to have been convicted over the bombing of Pan Am 103 in 1988.

The plane was on its way from London to New York on 21 December when it exploded above Lockerbie.

A total of 270 people died in the bombing, including everyone on board the plane and 11 people from the Scottish town.

Megrahi, who was found guilty of mass murder and jailed for a minimum of 27 years, died in 2012 after being released from jail on compassionate grounds in 2009. He had terminal cancer.

Media playback is unsupported on your device Media caption Stephanie Bernstein, whose husband Michael died in the bombing: "We've always known that there were other people involved"

Media playback is unsupported on your device Media caption Jim Swire, whose daughter, Flora, was killed: "I think that there is a need for evidence to be made available as to why these two are suspects"

Stephanie Bernstein, a US citizen whose husband was among those killed in the attack, said she was "surprised, delighted and really gratified" by the news that two further suspects had been identified.

"There are many, many people who I hope are not sleeping so well tonight knowing that the Scottish government and the US government are committed to pursuing this case," she said.

Frank Duggan, president of Pan Am 103 Relatives, which represents many of the US victims of the bombing, said he was not confident there would be further prosecutions.

"It's been 26 years. It's too long, people are dead, stories have been forgotten," he said.

"I'd like to think that it will be one small measure of closure but I don't expect the kind of justice that we all hope for."

But Dr Jim Swire, whose daughter died in the bombing, claimed that any prosecution would "need to be supported by very much better evidence" than that used against Megrahi, who Dr Swire believes was not responsible for the attack.

Analysis by Rana Jawad, North Africa correspondent

Image copyright Reuters

Abdullah al-Senussi is being held in Al-Hadba prison in Tripoli, but Masud's incarceration is less clear.

He is serving a 10-year sentence but there are conflicting claims over whether he is doing so in Tripoli or in a prison in Misrata.

The office of Tripoli's general prosecutor was less than forthcoming in divulging any information when it was contacted following the Crown Office announcement about the new suspects.

It is highly unlikely that any government in Libya would agree to any extradition request from the US or Scottish authorities to interview the two men.

Abdullah al-Senussi in particular (unlike his shadowy co-suspect) is not an ordinary figure; he is and will forever remain Gaddafi's black box on every crime, atrocity, and back-door dealings that Libya was allegedly involved in during his time in power.

There was always suspicion in Libya that the West wanted to get its hands on him specifically for that reason, and would subsequently never return him.

Investigators would have a better chance trying to interview the men on Libyan soil, a prospect that is complicated given the fact that there are no Western diplomatic missions operating in Libya and no government in Tripoli that the international community recognises.

Both of the newly identified suspects are currently serving prison sentences in Libya, which is in chaos as rival factions fight for control of the country.

Senussi, who was sentenced to death in July, is in a Libyan jail. He is appealing the verdict. He was the brother-in-law and intelligence chief of former Libyan dictator Colonel Gaddafi.

Masud is reported to be serving a prison sentence for bomb making.

Neither of the suspects are in the hands of the recognised government based in Tobruk but are being held by the Islamist-backed administration based in Tripoli.

A request to interview the suspects had been "routed through the British Embassy", the Crown Office said.

Relatives of some of those killed in the bombing welcomed the naming of two new suspects

Media playback is unsupported on your device Media caption How victim's brother tracked down Lockerbie suspects

Both men were named as possible suspects by an American TV documentary last month.

Documentary maker Ken Dornstein's brother David died in the Lockerbie bombing.

He told the BBC's Today programme: "We went in with a list of names that had come from the original investigation, pulled out of the tens of thousands of pages of documents. I established many were dead or missing. Ultimately, I concluded there may be three people left."

On Masud, Mr Dornstein added: "Figuring out simply that he existed would solve many of the unanswered questions to the bombing because he was attached to Megrahi according to the best information there was, including at the airport in Malta on the day that the bomb was said to have been infiltrated into the baggage system and ultimately on to Flight 103."

Megrahi's part in the bombing has been called into question in a series of books and documentaries.

Lockerbie bombing: Key dates

Image copyright AP Image caption Abdelbaset al-Megrahi is the only person to be convicted of the bombing

21 December 1988: Pan Am Flight 103 from London to New York explodes over Lockerbie, killing 270 people

31 January 2001: Abdelbaset al-Megrahi is found guilty of mass murder and jailed for life

20 August 2009: Megrahi, who has terminal cancer, is released from prison on compassionate grounds, and returns to Libya

20 May 2012: Megrahi dies at home in Tripoli, aged 60

15 October 2015: Scottish prosecutors request permission from Libya to interview two new suspects

Key developments in Lockerbie bombing case