THEY gathered in their thousands in London’s Trafalgar Square to pay a dignified and defiant tribute to the victims of the Westminster terror attack.

Multi-faith leaders, local residents, tourists, police and politicians gathered at the candlelit vigil, where a minute’s silence was observed for those caught up in the terrorist’s evil act, that left three people dead and 40 injured, including five critically.

Sadiq Khan, the London Mayor, told the packed venue: "Those evil and twisted individuals who tried to destroy our shared way of life will never succeed and we condemn them.

"The victims were people who came from all corners of our world. This a time to express our gratitude to the heroism of our police officers and emergency services, who ran towards danger to help and at the same time they encouraged others to run for safety.”

Amber Rudd, the Home Secretary, also paid tribute to the "courageous and brave" police officer Keith Palmer, who was stabbed to death by the Westminster terrorist, defending Parliament.

A fundraising appeal for his family has already topped £250,000. One MP called for a memorial to be erected in Mr Palmer’s honour while another said he should be considered for a posthumous bravery award.

Drawing applause from the crowd, Ms Rudd said of the attack: "They will not win, we are all connected and we showed that today by coming together, by going to work, by getting about our normal business, because the terrorists will not defeat us, we will defeat them.”

The defiant message came as the Home Secretary was forced to deny that intelligence failures were to blame for Wednesday’s attack.

The terrorist was named as 52-year-old Khalid Masood, born in Kent but who had been living in the West Midlands. He used a number of aliases and Scotland Yard suggested Khalid Masood was not believed to be his birth name. He is said to have worked as an English teacher.

On Wednesday afternoon, after driving a 4x4 vehicle into pedestrians on Westminster Bridge, he managed to break through the cordon outside the House of Commons and stab to death PC Palmer. It is believed he was fatally shot by the personal bodyguard of Sir Michael Fallon, the Defence Secretary.

So-called Islamic State claimed him as one of its "soldiers,” who had answered "calls to target citizens of coalition nations".

It transpired that Masood had a string of criminal convictions, including possession of a knife. Some years ago, he was investigated in relation to concerns about violent extremism but was regarded as a "peripheral figure" by the intelligence services. He had not been convicted of any terrorism offences.

"The fact that he was known to them doesn't mean that somebody has 24-hour cover," declared Ms Rudd, who warned people not to point "any finger of blame" at MI5.

The Home Secretary insisted the intelligence services did a "fantastic job" and people should "give them the space they need" to do it.

She also revealed Masood had spent time in jail but noted how it was not for terrorist-related offences.

As police and intelligence agencies mounted a massive investigation to piece together the terrorist’s movements in the lead-up to the attack, other developments included:

*a controlled explosion on a package took place last night on Birdcage Walk near the rear of Downing Street;

*searches were carried out at three addresses in Birmingham and one each in east London, Brighton, south east London and Carmarthenshire;

*a 39-year-old woman was arrested in east London while a 21-year-old woman and a 23-year-old man were held at one address in Birmingham;

*a 26-year-old woman and three men aged 28, 27 and 26 were arrested at another address in Birmingham and

*they were all held overnight while a 58-year-old man was arrested yesterday morning at a third address in Birmingham.

In the Commons after a minute’s silence was observed for the victims, Theresa May addressed MPs and delivered a defiant message, insisting: “We are not afraid and our resolve will never waver in the face of terrorism.”

She too paid tribute to PC Palmer, saying: "He was every inch a hero and his actions will never be forgotten."

Meantime, the identities of the terrorist's victims on Westminster Bridge emerged; one was a US tourist from Utah celebrating his wedding anniversary, the other a "highly regarded and loved" member of a London’s college staff.

Kurt Cochran and his wife, Melissa, were on the last day of a trip celebrating their 25th anniversary, and were visiting her parents, who are serving as Mormon missionaries in London, when Mr Cochran was mown down by the terrorist’s car. Mrs Cochran was badly injured.

Aysha Frade, who worked in administration at independent sixth-form school DLD College London, in Westminster, is understood to have been 43 and married with two daughters.

Forty other people were injured in the attack. Some 29 were being treated in hospital, where five remained in a critical condition on Thursday evening, two with life-threatening injuries.

The casualties included 12 Britons, three French children, two Romanians, four South Koreans, two Greeks, and one each from Germany, Poland, Ireland, China, Italy and the United States.

Three police officers were also hurt, two of them seriously.

Earlier, Mrs May paid a 40-minute visit to a hospital to meet some of the victims and speak to clinical staff.