Manchester suicide attacker Salman Abedi bought most of the components used to make the bomb himself, police have said.
Many of the bomber’s movements and actions were “carried out alone” in the four days prior to the attack, Russ Jackson, head of the North West counter terrorism unit, said. But police have yet to rule out whether he was part of a wider network.
Three men arrested over the attack were released without charge on Tuesday.
Det Ch Supt Jackson said much of the police investigation had been working through Abedi’s last movements. Officers have examined his movements on CCTV and other interactions he had with people as well as phone calls he made.
“Our enquiries show Abedi himself made most of the purchases of the core [bomb] components and what is becoming apparent is that many of his movements and actions have been carried out alone during the four days from him landing in the country and committing this awful attack,” said Det Chief Supt Jackson.
A powerful vehicle bomb has hit the diplomatic area of the Afghan capital, Kabul, killing at least 80 people and injuring 350.
It struck close to the German embassy in Zanbaq Square, with civilians said to be the main casualties. The morning rush-hour blast was so strong it blew out windows and doors hundreds of metres away.
No group has yet said it carried out the bombing, but the Taliban and IS have both been behind recent attacks.
The bomb went off at about 08:25 local time (03:55 GMT) during rush hour in the diplomatic quarter. Makeshift ambulances carried wounded away from the scene, as frantic relatives gathered both at the cordoned-off perimeter of the blast site and later at hospitals to try to locate loved ones.
Images showed dozens of blackened and burned out cars. More than 50 vehicles were destroyed.
Basir Mujahid a spokesman for Kabul police, told Reuters news agency the explosion had taken place close to the German embassy but added it was “hard to say what the exact target is”.
So-called Islamic State (IS) has claimed it was behind an attack on a bus carrying Coptic Christians in Egypt that killed at least 29 people and wounded about 25 others.
Masked men boarded several vehicles carrying the Christians and opened fire at close range, witnesses said. The funerals of some of the victims were held on Friday night.
Egyptian aircraft struck “terrorist training camps” in neighbouring Libya in retaliation for the attack. President Abdul Fattah al-Sisi said six strikes hit the Libyan town of Derna. President Sisi said he would “not hesitate to strike terrorist camps anywhere”.
Announcing the strikes in a TV speech late on Friday, the president promised to “protect our people from the evil”. He called for countries that support terrorism to be punished while appealing to US President Donald Trump for help.
Military sources told Reuters news agency that the militants targeted in Libya were involved in the attack on Egyptian Christians earlier on Friday.
A man who killed a policeman before holding authorities at bay for 18 hours has been shot dead in Australia.
On Monday, Rick Maddison fatally shot Senior Constable Brett Forte after the police officer intercepted his car in Queensland. He fled to a nearby farmhouse and spent the night in a stand-off with police.
Maddison was killed by authorities after fleeing the house and firing on police, Queensland Police Assistant Commissioner Tony Wright said. “He has been challenged by police at that point in time – he has fired at those police,” he told reporters on Tuesday. “Specialist police have returned fire. The male person has been shot and that male person has been declared deceased at the scene.”
Mr Forte was killed after intercepting Maddison, who police had described as a “wanted person”, about 14:20 local time (04:20 GMT) on Monday.
Authorities had set up an exclusion zone around the farm and began negotiating with Maddison at midnight. The confrontation happened just after 11:00.
Manchester Victoria railway station has reopened more than a week after the suicide attack at the city’s arena.
The station, attached to Manchester Arena, was shut after the bombing at the Ariana Grande concert, which left 22 people dead and dozens injured.
More CCTV footage of bomber Salman Abedi has been released and police are appealing for people who might have seen him carrying a blue suitcase.
Forensic teams have also been seen searching a landfill site in Bury. British Transport Police said its officers would be on patrol at the station on Tuesday.
Greater Manchester Mayor Andy Burnham and Transport Secretary Chris Grayling were among those to lay wreaths at the station as it reopened. Mr Burnham said: “People went above and beyond what you would expect. Those who rushed into the danger were station staff. “In these moments, you do see the best of people, you see the best of our public services and it is quite awe-inspiring to hear that.”