Armed police have arrested a 19-year-old man in a raid of the former home of the Manchester suicide bomber, Salman Abedi.

Residents described their houses shaking and hearing a loud blast as officers forced their way into the semi-detached property in Searby Road in the Gorton area of Manchester at about 7pm on Sunday. Abedi was listed at the property along with his older brother, Ismail, who was arrested shortly after the terror attack on Monday and remains in police custody.

Teresa McDowell, a resident of the area, said: “We heard this really loud explosion and then the police were everywhere. We’ve never seen anything like it before. We had no idea what was going on. The bang was so loud that my daughter who lives a 15-minute walk away also heard it.”

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Another resident, who wanted to remain anonymous, said a Libyan man who had lived in the house for about a decade had been arrested. He said: “It was the Libyan lad and they put him in the back of the police van. They did the door with an explosion and then they all went in and we saw them getting him out. I’m not sure what his name is but he’d lived here for a long time.”



Earlier, screams and a blast were heard as armed police raided another property elsewhere in Manchester.



Residents reported hearing explosions near Quantock Close and Selworth Road in the Moss Side area shortly before 2pm on Sunday. Dogs were seen at the scene and police closed off roads in the area. The street was cordoned off and shouts could be heard at about 3pm as a man was held on the ground at gunpoint before being put in a police van. Neighbours said the family in the raided house were Libyan. Another address in Rusholme was raided on Sunday evening but no arrests were made.

The police activity continued in the early hours of Monday when a 23-year-old man was arrested in Shoreham-by-Sea, Sussex, on “suspicion of offences contrary to the terrorism act”, Greater Manchester police said, bringing to 14 the number in custody related to the Manchester attack inquiry. There were also raids on addresses in Whalley Range and Chester but no arrests.

The raids came six days after the attack at Manchester Arena carried out by Salman Abedi, which killed 22 people and injured dozens more.

Fifteen people have now been arrested in connection with the investigation, two of whom have since been released without charge. Thirteen men remain in custody for questioning. Shortly after the raid on the house in Moss Side, a note could be seen pinned to the door saying the occupants had nothing to do with last Monday’s bombing.



Shortly after the raid in Moss Side, police released a statement saying they had also arrested a 25-year-old man in the Old Trafford area on suspicion of offences contrary to the Terrorism Act.

Stephen Cawley, who lives on the Moss Side street where the raid took place, said his neighbours’ children had been taken away by the police. Two brothers, believed to be aged about 19 and 15, were taken from the Sadigh household while the eldest son, aged 24, was forced to the ground and had a gun pointed to his head, neighbours said. All were later released.

One resident said they heard one of the boys complaining about “police brutality” before walking down the street.



The family later posted a notice on their damaged front door. It read: It read: “This is what the police has caused and we have nothing to do with what happened in the bombing attack.”

Facebook Twitter Pinterest A note written by the residents of the house in Quantock Street in the Moss Side which was raided by police on Sunday. Photograph: Anthony Devlin/Getty Images

The teenagers’ parents were being spoken to by police in a car parked on the road. The whereabouts of their two youngest siblings, a boy and a girl, were not known.



Cawley said the family had lived in the house for about a decade. He described the father as a handyman and said the family were “no trouble”.



He said: “Me and my wife were sat in the kitchen and we heard what sounded like a bomb going off. It frightened the life out of us. It was so scary. Just such a loud bang and then there was the army and police everywhere and dogs.



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“It was the eldest lad who had the gun pointed at his head because he was resisting – but then they let him go. The other two have been taken in and the mum and dad are sat in a car opposite.



“We’re not allowed to leave the house. My grandchildren were meant to be coming round for Sunday dinner but we’ve been told to cancel everything and stay inside.”



One of the boys who is suspected of being arrested, changed his Facebook profile picture to include the message: “#PrayforManchester We are with you!” on Saturday night.



A spokesperson for Greater Manchester police said: “During the search, three men were arrested on suspicion of offences contrary to the terrorism act but were soon after de-arrested.”



Images posted on social media showed armed officers in Moss Side amid reports of an explosion. Police would not comment on whether a controlled blast was used to gain entrance to the property, a tactic used on previous raids.



One resident wrote on Twitter: “There was an explosion about half an hour ago on Selworthy Road, Moss Side. There is armed police and dogs surrounding the area.”



As the huge counter-terror operation continued, the NHS said 54 people injured in the attack were still being treated in eight hospitals, with 19 receiving critical care. A total of 116 people required hospital care, police previously said.



The latest police operation came just hours after the home secretary said members of bomber Abedi’s terror network could still be at large. Amber Rudd said parts of the suicide attacker’s circle were “potentially” unaccounted for, despite optimism that a previous wave of arrests had quelled further threats.

On Saturday night, police issued CCTV stills of Abedi, wearing glasses and casual clothes, in a plea for information about his movements between 18 May and the attack. Hours after he was captured on camera, the 22-year-old was dead, having attacked a concert by American singer Ariana Grande attended predominantly by young girls.



The huge police response that followed involved raids in several cities as counter-terror efforts focused on cornering his suspected criminal ring.



The Guardian understands investigators believe Abedi had help in storing the materials, buying the chemicals to make the homemade explosive and obtaining bolts and screws that were wrapped around the device. The metal shrapnel was particularly deadly, with the force of the explosion causing a spray of lethal projectiles in the foyer of the Manchester Arena.



Facebook Twitter Pinterest Police at a cordon in Quantock Street, Moss Side. Photograph: Jonathan Brady/PA

It is also believed that Abedi had assistance in designing the device and that it is unlikely he merely got instructions from the internet. He was involved in building the device and may have had help in this, or may have built it wholly on his own at a rented flat in Granby Street, in Manchester city centre.



The pursuit of members of the wider network that helped Abedi continues. Investigators believe they have the main players in custody and have accounted for all the known materials used to make the explosive device.

At other addresses, “dual use” items – those with everyday as well as dangerous applications – such as wire-strippers have been found.



The hunt continues for suspected less important conspirators as soldiers deployed on the streets prepare to return to barracks after the UK’s terror threat level was reduced from critical to severe.



Mark Rowley, Britain’s top counter-terrorism officer, said on Saturday: “We are getting a greater understanding of the preparation of the bomb. There will be more searches but the greater clarity and progress has led JTAC [Joint Terrorism Analysis Centre], the independent body which assesses threat, to the judgment that an attack is no longer imminent.”

Those in custody are Abedi’s family members, friends, people with Libyan heritage and others. Criminal charges are expected against some of those detained.