'Forgive me': Manchester concert bomber's last words before attack

New insight into Abedi's actions came as police extended investigation across Europe into Libya

The alleged culprit in a deadly concert bombing was driven by what he saw as unjust treatment of Arabs in Britain, a relative has said, confirming he made a final phone call to which he pleaded, "Forgive me."

Salman Abedi was particularly upset by the killing last year of a Muslim friend whose death he believed went unnoticed by "infidels" in the UK, said the relative yesterday, speaking on condition of anonymity over concerns for her own security.

"Why was there no outrage over the killing of an Arab and a Muslim in such a cruel way?" she asked. "Rage was the main reason," for the blast that killed 22 at the end of an Ariana Grande concert at Manchester Arena on Monday, she said, speaking by telephone from Libya.

The new insight into Abedi's motivation came as Britons faced stepped-up security, authorities pushed forward with raids and the investigation extended across Europe into Libya, where most of the suspected bomber's family lived.

The number of arrests in the UK ticked up to eight as British Transport Police said armed officers would begin patrols on some trains because of an increased threat of terrorism. Greater Manchester Police Chief Constable Ian Hopkins said, without elaborating, that searches of suspects' homes brought "very important" clues in the probe of the bombing. But leaks from the investigation were creating a trans-Atlantic diplomatic mess.

Manchester police halted their sharing of investigative information with the US through most of the day until receiving fresh assurance there would be an end to leaks to the media.

British Prime Minister Theresa May, who spoke about the matter with US President Donald Trump at a NATO summit in Brussels, said the countries' partnership on defence and security was built on trust. But "part of that trust is knowing that intelligence can be shared confidently," she said.

Trump pledged to "get to the bottom" of the leaks, calling them "deeply troubling" and asking the Justice Department and other agencies to "launch a complete review of this matter."

British officials were particularly angry over photos published by The New York Times showing remnants of a blue backpack which may have held the explosive. But it wasn't clear US officials were the source of the images, which the Times defended as "neither graphic nor disrespectful of victims" and consistent with basic reporting "on weapons used in horrific crimes."

British security services were also upset that 22-year-old Abedi's name was apparently leaked by US officials while police in the UK continued withholding it and while raids were underway in Manchester and in Libya. Hopkins said the leaks "caused much distress for families that are already suffering terribly with their loss."

Meanwhile, the investigation into the blast widened. Authorities chased possible links between Abedi and militants in Manchester, elsewhere in Europe, and in North Africa and the Middle East. They were exploring potential ties to Abdalraouf Abdallah, a Libyan jailed in the UK for terror offences, and to Raphael Hostey, an Islamic State recruiter killed in Syria.

Abedi's family remained a focus, too, with a brother in England, his father and another brother in Libya among those detained. Abedi's father was allegedly a member of the al- Qaida-backed Libyan Islamic Fighting group in the 1990s, a claim he denies.