ANTI-terror cops have swooped on a home directly opposite Heathrow Airport after a second man was arrested in the hunt for the Parsons Green bomber.
However, the classification means they think an attack is still highly likely. Police have not provided details about the extensive search, which began two hours after an 18-year-old suspect in the subway bombing was arrested at Dover's ferry port.
Police are continuing to search a house in Sunbury-on-Thames in Surrey.
Ronald Jones, 88, and Penelope Jones, 71 were rewarded for their service to children by the Queen, who made them MBEs in 2010.
The entire neighborhood around their house was evacuated as a precaution when the search began Saturday.
The threat level facing Britain remains at critical, interior minister Amber Rudd said on Saturday, as she praised the police for making a "very significant" arrest following a London train bombing which injured 30 people a day earlier.
The whole road remains cordoned off and police have erected a large grey fence around the front of the Jones's home.
Green says "I would urge anyone from the president of the United States on downwards not to tweet" about activities during an active police terror investigation.
Rudd made the comments on BBC's Andrew Marr Show on Sunday, after Trump claimed the person who carried out the attack was known to British police.
He was arrested by detectives investigating the bucket bomb that partially detonated at the underground station, police have confirmed.
On Sunday, Scotland Yard said that a 21-year-old man had been arrested in Hounslow, south-west London, shortly before midnight.
Her announcement came after two people were arrested in connection with the blast.
On Saturday morning, police arrested an 18-year-old man in connection with the attack at Dover.
The UK's terror threat level has been downgraded from critical - meaning an attack is imminent - to severe.