The human remains found in two suitcases dumped on the Clifton Suspension Bridge were those of two men, Scotland Yard has confirmed.
The update from the Metropolitan Police came as the force announced its officers will be taking over the manhunt for the suspect.
Investigators believe he travelled to Bristol from London earlier and have sealed off a new crime scene in Shepherds Bush.
Deputy Assistant Commissioner Andy Valentine, who is leading the investigation for the Met, said: ‘Over the last 48 hours we have been working extremely closely with colleagues from Avon and Somerset.
‘This work leads us to believe the man we need to speak to travelled to Bristol from London earlier on Wednesday evening of July 10.
‘We are drawing on resources from across the Met to find and apprehend the suspect and I would urge anyone who believes they see him, or who knows of his whereabouts, to call 999 straight away. Do not approach him.
‘We recognise this has caused significant concern to residents in the Clifton area and will cause concern among those who live and work in West London.
‘Extra officers will be on patrol in the area over the coming days and I would encourage anyone with any concerns to speak to them.’
The grim discovery was made after police were called to reports of a man with a suitcase acting suspiciously on Clifton Suspension Bridge at 11.57pm on Wednesday.
Witnesses described how the suspect, who arrived at the bridge in a taxi, was challenged after one of the ‘tatty’ suitcases was seen to be leaking blood.
He may have been stopped from throwing the heavy cases over the side and into the gorge 25ft below by the safety railings, reports suggest.
Despite officers arriving less than 10 minutes after staff raised the alarm, the suspect fled towards the Leigh Woods area, leaving the suitcase behind. A second was found nearby a short time later.
Avon and Somerset Police has released two pictures of him, showing a black man with a beard, wearing a black Adidas baseball cap, black jeans, a black jacket and black trainers with thick white soles and carrying a black backpack.
The force have urged people not to approach him and call 999 if he is sighted, but have said they are unaware of any current risk to the wider public.
Witnesses described seeing two men with suitcases in the Clifton area of Bristol, a short distance from the bridge, on Wednesday evening.
Giles Malone told ITV News West Country he had been waiting for an Uber near The Mall pub when he saw two men lifting suitcases across the road shortly after 10.30pm.
He said: ‘We were stood there waiting for our car and a man and another man got out of another car across the street and they were lifting these suitcases across the road for some reason, right by us.
‘Another lady started to help them and the lady who was helping them said “These are the heaviest suitcases I’ve ever lifted – what’s in them, bodies?”’
Mr Malone, who lives in North Carolina but is in Bristol visiting his father, described the cases as ‘big’ and ‘tatty’, ITV News West Country said.
Another passer-by who was crossing the bridge with his girlfriend at the time described seeing ‘blood on the bridge and one case’.
The man, who did not wish to be named, told Bristol Live they saw a cyclist chasing the suspect.
He went on: ‘We got back to the bridge at around 11.55pm, spoke to the staff, and they called the police, and we waited for the police to arrive.
‘There were two suitcases, one left on the bridge with what appeared to be blood leaking from it, the other case was on the road just after the bridge on the Leigh Woods side.
‘There was blood on the floor along the bridge.’
Council cleaning teams attended on Thursday evening, with the bridge then reopening at just after 11pm.
Speaking on Friday morning, Acting Bristol Commander Vicks Hayward-Melen said searches were continuing to locate the suspect.
She told BBC Radio 4’s Today programme: ‘We’re still looking for him to speak with him about his presence on the bridge and the matters leading up to the suitcases being located.
‘With regard to the officers and the initial attendance and then what they found inside, clearly a really horrendous discovery for them and we’re making sure we continue to support them.’
She confirmed that a forensic post-mortem examination on the remains, which began on Thursday, continued on Friday.
Mrs Hayward-Melen added: ‘The process is complex and lengthy, working with the forensic pathologist. It’s still ongoing at this time.’
She confirmed the suspect was taken to the bridge in a taxi, which has been seized by police.
The taxi driver is helping officers with the investigation.
When asked about the cyclist following the suspect, she said police were appealing for witnesses with information ‘no matter how small’ to come forward.
She said this included ‘anybody who may have had any interaction with the individual’.
Mrs Hayward-Melen added: ‘We’ve got no information to suggest they pose an active risk to wider members of the public but clearly we do want to speak to them, so we would advise (calling) 999 immediately please if you see anybody matching the description of the man I showed the photograph of yesterday.’
Police said officers have been in contact with the family of missing Jack O’Sullivan to ‘inform them of the incident’ but said ‘no parallels are actively being drawn’.
The 23-year-old was last seen at about 3.15am on March 2 in the area of Brunel Lock Road and Brunel Way in Bristol.
Clifton Suspension Bridge, a Grade I listed landmark which spans the Avon Gorge, was designed by noted Victorian engineer Isambard Kingdom Brunel and opened in 1864.
Carla Denyer, the Green MP for Bristol Central, said on Thursday: ‘I am deeply disturbed by the horrifying discovery of human remains at Clifton Suspension Bridge overnight.
‘Distressing events like this are unsettling for all of us who call Bristol home and are proud of our city.’
She thanked police for their work on the case.
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