CCTV footage could show the Parsons Green attacker leaving home with a bomb an hour and a half before the tube train explosion which injured 30 people.

The partial explosion of a homemade device inside a Lidl bag on a packed London Underground train at Parsons Green station in west London on Friday morning was the fifth terror incident this and temporarily saw the terror threat level raised from 'severe to critical'.

ITV obtained video footage showing a man leaving a house in Surrey - carrying a large Lidl carrier bag at 6.50am - 90 minutes before the 'fireball' tore through the packed train carriage.

The property in Sunbury-on-Thames has since been raided by armed police who evacuated all neighbouring homes within 100 metres.

Photos of the bomb on board the train appeared on social media within minutes of the attempted atrocity.

It comes as dramatic footage emerged showing armed police storm the Sunbury home, belonging to two foster carers, where the suspected bomber, 18, is believed to have lived.

In the video, officers wearing bulletproof body-armour can be heard shouting: "Armed police, open the door now."

CCTV still issued by ITV News appearing to show a person walking with a Lidl bag on the morning of the Parsons Green terror attack. The footage is reported to have been filmed near a house in Sunbury-on-Thames, Surrey, which is at the centre of one of two police raids.

The home belongs to to Penelope and Ronald Jones, aged 71 and 88 respectively, who previously received MBEs for services to children and families.

The couple, who have been foster parents for almost 40 years, have taken in up to 300 children, including eight refugees.

One of their foster children is believed to have been the bombing suspect, who was arrested at the Port of Dover just before 8am yesterday morning.

A local politician said the 18-year-old was an Iraqi orphan who had moved to Britain aged 15 after his parents died.

Leader of Spelthorne Borough Council Ian Harvey, whose ward is Sunbury East, said he learnt about the boy's background from neighbours of Mr and Mrs Jones and information available publicly.

He said: "One thing I understand is that he was an Iraqi refugee who came here aged 15 - his parents died in Iraq."

It comes as a second home was raided in Stanwell, Surrey - just several hundred yards from Heathrow Airport - in connection with the bombing.

This followed the arrest of a second suspect, 21, in the London borough of Hounslow on Saturday night. Both men remain in police custody.

Travellers walk on the platform at Parsons Green tube station following Friday's incident on a tube at Parsons Green Station in London

Home Secretary Amber Rudd said police had made "good progress" in the investigation as she announced the country had been removed from the highest terror alert - from "critical" back down to "severe".

Jim Adaway, a family friend of Mr and Mrs Jones, said they recently returned to foster caring to help resettle youngsters from overseas.

The 37-year-old said Mrs Jones had been struggling with one of the children in their care.

The couple are said to be staying with friends following the police raids, during which surrounding houses were evacuated by counter-terror officers, with residents told they had "one minute" to flee their homes.

Local residents said the man living at the second address being searched in Stanwell is a light-skinned man of Arabic appearance.

According to a couple, who asked not to be named, he habitually stayed up late at night and was often visited by two male companions, who appeared to be in their late teens.

The husband said: "He seemed a really, really nice chap, we have sat there and had a drink with him, but he didn't drink alcohol.

"He was from North Africa, I think, perhaps Morocco or Algeria, but he had family from Scotland. I think he moved in about 14 months ago, he was very quiet, he was on his own."

His wife added: "To me he just kept himself to himself, he wasn't involved with us or the neighbours, but he seemed to be up at unusual hours."

Fireman talk within the police cordon at Parsons Green Underground Station

Thirty people were injured when the improvised device exploded during rush hour at Parsons Green station, with all but one now discharged from hospital.

The lowering of the threat level from critical to severe means another attack is no longer imminent, but still highly likely.

Mayor of London Sadiq Khan said: "I would urge all Londoners to remain vigilant over the days ahead.

"You will see more police - including armed officers - on the streets and transport network throughout the week. They are there to keep us safe.

"London's response to this attack shows once again that we will never be intimidated by terrorism."

Armed police will maintain a strong presence across the country, while military personnel drafted in to provide support will be phased out.

Assistant Commissioner Mark Rowley, the country's top counter-terrorism police officer, said: "The high pace and rapid progress of this investigation is continuing.

"There was another arrest overnight and two men are in custody. There are now two searches continuing at addresses in Surrey and we are getting a greater understanding of the preparation of the device."

The Metropolitan Police said yesterday: "At approximately 7.50am, local police officers in Kent arrested an 18-year-old man in the departure area of the Port of Dover.

"He was arrested on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism. He has now been transferred to custody at a police station in London.

Handout photo issued by Richard Aylmer-Hall of emergency services attending an incident at Parsons Green station in west London amid reports of an explosion

"A short while later, at around 1.40pm - with the assistance of Surrey Police - Met Police officers also evacuated a house in Sunbury-on-Thames. As a precautionary measure, we evacuated the surrounding buildings and set up cordons within a 100-metre radius."

  • Anyone with information on the attack is urged to call the Anti-Terrorist Hotline on 0800 789 321. In an emergency, always call 999
  • Anyone with footage or images from the incident at Parsons Green is asked to upload them at www.ukpoliceimageappeal.co.uk where they will be looked at by investigators