Dominic Casciani
Home Affairs Correspondent

The investigation into Manchester bomber Salman Abedi's connections has already branched out in multiple directions.

Tracking people before they commit terror acts could be over in hours - or it could take weeks.

At any one time, MI5 is handling in the region of 500 active investigations involving 3,000 "SOIs" - "subjects of interest" in security world jargon.

What kind of resources does MI5 have to throw at those targets?

Read more from Dominic here.

The mother of an 18-year-old student killed in the Manchester attacks has thanked "well wishers" at a vigil in the town where she studied.

Image source, Instagram Georgina.Bethany

Georgina Callander studied at Runshaw College in Leyland.

Her mother said at the end of the vigil staged at Worden Park the kind thoughts had been" very much appreciated" and that her "loving daughter" would be looking down with her usual big smile.

The BBC's political correspondent, Iain Watson, says the owner of the unattended car on Westminster Bridge has been found and the cordon is being pushed back.

Police have closed off Westminster Bridge, Scotland Yard has confirmed.

A statement from the force said they were alerted to an unattended vehicle left on the bridge just after 17:45 BST.

It added: "Officers are now in attendance and there are road closures in place. Inquiries continue. No further information at this time."

These are pictures of a flat in Granby Row, Manchester, suspected bomber Salman Ramadan Abedi may have used before the attack on Monday night.

Police raided the flat on Wednesday.

US Secretary of State Rex Tillerson will make his first official visit to the UK on Friday.

He is due to meet with UK Foreign Secretary Boris Johnson and they will both write messages of condolence for the victims of the Manchester attack.

The Foreign Office said it was "an expression of UK-US solidarity" following the attack.

Home Secretary Amber Rudd has paid tribute to detective constable Elaine McIver, an officer with Cheshire Police who was killed during Monday's attack.

She said: "Elaine was off-duty at the time of this brutal, cowardly attack, going about her normal daily life.

"My thoughts and prayers go out to her family and to everyone who has been affected by this horrendous act.

"I also want to pay tribute to Elaine's colleagues at Cheshire Police who, despite the overwhelming sense of loss I know they must be feeling, have continued to perform their duties, keeping people safe with the same diligence and professionalism on which we all rely."

Image source, Greater Manchester Police

Jahan Mahmood, former anti-terrorism advisor to the government, told the BBC News Channel that there had been a "failure" by authorities after friends of Salman Abedi had contacted the anti-terror hotline about him.

"There has been this constant questioning and interrogation of the Muslim community as if they are not part of this nation, that they don't anything," he said.

"If anything we have to remember that these terrorists are the enemy of British Muslims, as well as mainstream British society, and we are all in it together."

People are starting to arrive at Worden Park in Leyland where a vigil is being held for two of the victims of Monday's Arena attack.

Image source, PA

Eight-year-old Saffie Roussos, from Tarleton, Leyland, was the youngest victim of the blast and Georgina Callander, 18, was a student at Runshaw College in the town.

The vigil is to be staged at Worden Park between 17:30 and 18:00 on Thursday.

Gwent Police have confirmed a second suspicious item has been found in Newport.

At around 3.30pm, the force evacuated and cordoned off the Friars Walk shopping centre, and bomb disposal teams have been on the scene.

Now, police have also closed off the area surrounding George Street Bridge and are asking people to avoid the area.

Anthony Zurcher
BBC North America reporter

Leaks that have bedevilled the US government for months are now on international display.

Manchester police have begun withholding details of Monday's attack from US intelligence after a series of leaks - including the printing of close-up photographs of fragments of the Manchester bomb in the New York Times.

So who, exactly, benefits from divulging sensitive information?

Read more from Anthony here

Greater Manchester Police have confirmed that the explosive ordnance disposal team (EOD) are helping them with the search of a property in Withington, Manchester, following an arrest last night in relation to Monday's bombing.

The force also confirmed they were currently searching a property in Moss Side following another arrest last night, also related to the attack.

Former Labour home secretary Jacqui Smith said the decision from the Conservative government to cut police numbers has had "implications for people's safety".

She said it was "simplistic" to link the cuts to Monday's attack, but she told BBC 5 Live: "I think it's pretty clear that my party, and I in fact, think that reducing police numbers by 20,000 isn't something that you can do without implications for people's safety."

Asked if that meant she thought Mrs May had "let people's safety down", Ms Smith replied: "Yes, by reducing police numbers by 20,000, I believe so."

Gwent Police are still on the scene at Friars Walk shopping centre in Newport after reports of a suspicious vehicle.

Bomb disposal crews have been seen, as well as other emergency services vehicles.

Blackpool staged two minutes' silence at 12:00 to remember Jane Tweddle-Taylor from the resort who died in the Manchester attack.

Blackpool Tower is being lit up in the union jack's red, white and blue colours and a book of condolence open to sign all week in honour of the 22 killed in the explosion.

A crowdfunding page set up to buy a drink for emergency staff who have helped Manchester Arena attack victims has raised more than £10,000.

Image source, PA

Edmund Hall, a lifeboat volunteer from London, said: "I listened to the awful news the morning after the bombing and thought I'd like to put a few quid behind the bar at a pub near the Manchester Royal Infirmary.

"I know alcohol isn't the answer to the stress and trauma that the emergency services have experienced... but it seems a simple and easy way to say thank you."

He said he was "speechless" at the response.

Monday's victims, including Coronation Street superfan Martyn Hett, are to be immortalised on a bench on the soap's set.

The bench, which is a tribute to all 22 people killed, will be revealed in an extension to the set in Trafford in the coming weeks.

Mr Hett, 29, was an avid viewer and had a tattoo of one of the show's character's, Deirdre Barlow.

Image source, BBC/Hett Family