Salman Abedi, the British-born man who killed 22 people at a concert on Monday (May 22) in the worst terror attack in Britain since 2005, was born to Libyan emigre parents and grew up in a devoutly Muslim family in Manchester, family friends and neighbours say.
His two brothers and father have been taken into custoday in Britain and Libya as investigators try to uncover what is believed to be a network of terror behind the May 22 bombing fronted by Abedi.
Here is what we know about the Abedis.
Salman Abedi, 22
Acquaintances were stunned to learn that Salman had carried out the suicide bombing but there were signs that he was troubled, friends and officials said Wednesday.
He was born in Britain to parents who had fled Libya during the four-decade dictatorship of Muammar Gaddafi. In the Libyan-British community in southern Manchester where Salman lived, he was known as a university dropout, an "awkward" young man and an "isolated, dark figure" who talked to few people and travelled back and forth between Britain and Libya.
People who knew the family said Salman cared for his parents. "He really liked them," said Mohammad Fadi, 25, standing in front of the mosque where the family had worshipped.
But members of the Libyan immigrant community reported to local authorities that they feared Salman was turning increasingly radical, two friends of the family said.
British security authorities have acknowledged that they were aware of Abedi but said that he was not considered a major terrorism risk.
His father Ramadan told the Associated Press early Wednesday that he believed his son was innocent. "Last time I spoke to him, he sounded normal," the father said in a telephone interview from Libya.
When his parents moved back to Libya a few years ago after Gaddafi was deposed, Salman and his brothers stayed behind in Manchester. He and younger brother Hashem were ordered by their father to move to Libya several weeks ago, said a friend of the family who last spoke to Ramadan on Tuesday.
Salman told his parents about a week ago he wanted to travel to Saudi Arabia to prepare a pilgrimage to Mecca, according to one family friend and a Libyan official."But he was lying," said Ahmed Dagdoug, a spokesman of the Libyan counterterrorism Reda Force, which is aligned with the Libyan government that is recognised by the United Nations.
Instead of going to Saudi Arabia, Abedi flew back to Britain, where he carried out the worst terrorist attack on British soil since the London bombings in 2005.
Hashem Abedi, 20
Salman Abedi was not the only one in his family who caused concern in Manchester. His 20-year-old brother Hashem was arrested in Libya late Tuesday night by the Special Deterrence Forces, according to officials there.
The officials said the young man told authorities that he had been involved in planning the May 22 Manchester attack.
A friend of the Abedi family said Salman and his brother Hashem had changed after another youth - an 18-year-old Manchester resident also of Libyan descent - was killed in the northern British city a year ago.
That teenager, Abdulwahab Hafidah, was stabbed in the neck in what local media reports called retaliation for his having gone into rival gang territory. Hashem Abedi appeared to have known Hafidah.
"It became a big source of anger for the youngsters in the Libyan community. Salman and Hashem saw it as an act of anti-Muslim hate crime; they called him a martyr," the family friend said.
In 2014, Hashem joked on Facebook about joining a militant group, commenting on the photo of a young British extremist who had left for the war in Syria: "Inshallah (God willing) we go together."
The younger brother's Facebook profile revealed other signs that he had an interest in the Islamic State in Iraq and Syria, which has claimed credit for the Manchester attack.
"Hashem helped Salman prepare for the attack," said Ahmed Dagdoug, a spokesman of the Libyan counterterrorism Reda Force, which is aligned with the Libyan government that is recognised by the United Nations.
"He had the same ideology as his brother."
While it is not known what part Hashem played in the Manchester attack, he told interrogators, according to Libyan officials, that "we knew what we were doing".
In a Facebook post, the Special Deterrence Forces, which operates out of a former US military base, said that Hashem had been an ISIS member, had been involved with the Manchester plot, and was en route to withdrawing 4,500 Libyan dinars (about US$560) sent by Salman when he was arrested Tuesday night by the militia.
The militia also said that the younger brother travelled from Britain to Libya on April 16, and that he had been in daily contact by phone with Salman since then.
The the younger brother was planning a new attack, in Tripoli, the militia claimed.
Better known as Abu Ismail to the Libyan community in Manchester, Ramadan worked as an odd-job man in the city and has been working for the Libyan police force in recent years, according to an official.
He was also detained by Libyan militia on Wednesday, authorities said, although it was not clear on what charges.
Ramadan reportedly emigrated to London from Libya with his wife to escape the regime of Libyan dictator Muammar Gaddafi. His four children were all born in Britain.
He sometimes led the call to prayer at the Manchester Islamic Centre, the local mosque also known as Didsbury mosque which Ramadan and his children attended.
Ramadan is a well-known figure within the Libyan community in Manchester, said a member the community.
“He used to do the five and call the adhan. He has an absolutely beautiful voice. And his boys learned the Quran by heart," the source said.
“Abu Ismail will be terribly distraught. He was always very confrontational with jihadi ideology, and this Isis thing isn’t even jihad, it’s criminality. The family will be devastated.”
Ramadan and his wife moved back to their homeland several years ago, after the Libyan leader was killed, but their children remained in Britain. He ordered Salman and Hashem to move to Libya a few weeks ago - an order which the young men complied with, but apparently failed to stop them from carrying out the Manchester attack.
Ramadan seemed incredulous that his son had carried out a terror attack and said he was sure Salman had not been an ISIS member.
"Salman doesn't belong to any organisation," he said. "The family is a bit confused because Salman doesn't have this ideology, he doesn't hold these beliefs."
"We condemn these terrorist acts on civilians, innocent people."
Ismail Abedi, 23
The oldest of Ramadan's four children and older brother of Salman and Hashem, Ismail has also been taken into custody since the attacks.
He is known to have volunteered at the Manchester Islamic Centre, also known as the Didsbury Mosque where the family worshipped.
SOURCES: WASHINGTON POST, REUTERS, NYTIMES, GUARDIAN