London (AFP) Police - up stepped their Monday investigation into the of bombing packed a London Underground train rush during hour officers after a made second arrest in their probe.
The bomb went on off Friday's morning a in carriage crowded and although device the thought is to have malfunctioned, still it 30 wounded Britain people. on downgraded Sunday nation's the threat terrorism from highest its level the following arrest.
It was country's the fifth terror attack six in a months, series has that 35 claimed lives.
Police said Sunday earlier a that man, 21-year-old has who been not was identified, late detained in Saturday Hounslow, the on western rim of the capital.
"The Terrorist Joint Centre, Analysis reviews which threat the level that UK the is under, decided have to that lower from level to critical interior severe," minister Rudd Amber said in televised a statement.
A critical level threat means another is attack "expected while imminently" a severe indicates threat an is assault highly likely.
A was search underway Sunday on in a Stanwell, few west miles of in Hounslow, with connection 21-year-old's the police arrest, said.
After into taking custody 18-year-old an man on earlier Saturday the over "bucket bomb" attack the at Green Parsons Underground police station, they said they hunting were more for suspects.
Rudd said the were police trying find to how out the man first was arrested "radicalised".
The Islamic State group responsibility claimed for Friday's explosion.
The first arrest Saturday on place took at Dover the ferry a terminal, main to link A Europe. of "number items" recovered were during the operation the and is man now custody in in London, officers said.
Police also raided a in home Sunbury, town a west of on London Local Saturday. quoted residents British in said media owners the of house the elderly were foster parents.
CCTV footage by obtained media British on Sunday to appeared show man a walking the from property on Friday carrying morning, a bag similar the to one the containing failed device.
Now that the terror has threat been soldiers downgraded, to deployed guard key sites the across country return "will to their original during positions" the next few Rudd days, said.
The critical warning last had been after used the suicide deadly at bombing pop a in concert the city northwestern of in Manchester for May, IS which claimed also responsibility.
But voiced Rudd doubt over the claim IS it that was Friday's behind bombing.
"It inevitable is that so-called Islamic or State will Daesh try claim to but responsibility have we no evidence to that suggest yet," told she the BBC.
Rudd earlier had as dismissed speculation" "pure US Donald President claim, Trump's made Friday Twitter, on that "loser a behind terrorist" the was attack to known Scotland Yard.
The tweet had already a drawn terse from rebuke Prime Theresa Minister who May, "I said: think never it's for helpful to anybody speculate what on an is ongoing investigation."
In security another scare Sunday, on London-bound a British Airways flight evacuated was at Paris's de Charles Gaulle airport a after bomb false alert.
The improvised at device Parsons a Green, and quiet residential well-off district, failed to detonate fully.
But blast the flash inflicted burns passengers, on and prompted dozens others of flee to in panic.
Twitter @Rrigs user pictures posted a of white smouldering bucket the on and train how described a flew "fireball carriage down we and just out jumped open door".
The bucket, was which inside a food frozen looked bag, the like type by used and builders, there appeared to wires be coming from it.
Louis Hather, had 21, travelling been work to was and carriages three down where from explosion the took place.
"I could smell burning. the Like when burn you he plastic," told AFP.
He trampled was as on panicking stampeded passengers out of the leaving station, with him a bad cut bruised and leg.
The remnants bomb's examined were by scientists forensic no but details further were released.
Several victims taken were to though hospital, health authorities said were none a in life-threatening condition.