London terror attack

People lay floral tributes to the victims of the March 22 terror attack in Parliament Square outside the Houses of Parliament in central London on Friday. Counter-terrorism police commander Mark Rowley said nine people are now in custody over the rampage in Westminster, in which at least 50 people were injured, 31 requiring hospital treatment.

Sheikh Mohammed al Hill, left, embraces Cardinal Vincent Nichols, Archbishop of Westminster, right, following a vigil outside Westminster Abbey, Friday, in London. Faith leaders came together and held a one minute silence today following the terror attack .

A woman looks at flowers in Parliament Square near Tuesday's rampage scene.

The Archbishop of Canterbury, Justin Welby, left, Sheikh Mohammad al Hilli, Sheikh Ezzat Khalifa, Chief Rabbi Ephriam Mirvis and Cardinal Vincent Nichols, Archbishop of Westminster, from left, arrive for a gathering of faith leaders take part in a vigil outside Westminster Abbey for the victims of Wednesday's attack.

A taxi drives down Westminster Bridge in London, Friday. A fourth person has died after Khalid Masood drove a car into pedestrians on Westminster Bridge before going on to fatally stab PC Keith Palmer on March 22.

Security guards search visitors to the London Eye, Friday.

People pause at the floral tributes to the March 22 terror attack victims.

An encouraging message is placed among flowers on Westminster Bridge in London, Friday.

A group of women hug outside the Police Memorial where flowers have been laid near to the scene of the latest London terror incident.

A single white rose hangs off the gates of The Houses of Parliament, Friday, after the terror incidents on March 22.

Members of the public light candles during a candlelit vigil at Trafalgar Square on March 23, 2017, in London.

Candles are lit at a tribute display during a a vigil for the victims of Wednesday's attack, at Trafalgar Square in London on March 23, 2017.

(L-R) The Mayor of London Sadiq Khan speaks as Home Secretary Amber Rudd MP and acting Commissioner of the Metropolitan Police Craig Mackey look on during a candlelit vigil at Trafalgar Square on March 23, 2017 in London.

Crowds fill Trafalgar Square in London on March 23, 2017 during a vigil for the victims of Wednesday's attack.

A woman holds up a sign at a vigil for the victims of Wednesday's attack, at Trafalgar Square in London on March 23, 2017.

Armed police officers secure the area on Whitehall leading toward the Houses of Parliament in central London on March 23, 2017 the day after the March 22 terror attack in Westminster claimed at least three lives including that of police officer Keith Palmer. Britain's parliament reopened on Thursday with a minute's silence in a gesture of defiance a day after an attacker sowed terror in the heart of Westminster, killing three people before being shot dead. Sombre-looking lawmakers in a packed House of Commons chamber bowed their heads and police officers also marked the silence standing outside the headquarters of London's Metropolitan Police nearby. / AFP PHOTO / NIKLAS HALLE'NNIKLAS HALLE'N/AFP/Getty Images ORIG FILE ID: AFP_MX30F

Britain's Prime Minister Theresa May speaks in the Houses of Parliament, March 23, 2017, following the attack in London Wednesday.

An undated handout picture released by The Church of Jesus Christ of Latter-day Saints on March 23, 2017 shows US citizens Kurt W. Cochran (L), who was killed in the March 22 London terror attack, and his wife Melissa (R) pictured at an undisclosed location.

People hold up a banner ahead of a candlelit vigil at Trafalgar Square on March 23, 2017 in London.

In this March 22, 2017 file photo, the attacker Khalid Masood is treated by emergency services outside the Houses of Parliament London. British Police named on March 23, 2017, Khalid Masood as The Houses of Parliament attacker.

Members of the public walk along Westminster Bridge in central London on March 23, 2017 after it reopened following the March 22 terror attack at the British parliament.

Forensic police officers search the ground in Parliament Square outside the Houses of Parliament in central London on March 23, 2017 as the investigation continues after the March 22 terror attack.

Police officers arrive with a bunch of flowers to lay in honour of police officer Keith Palmer, who was killed during the March 22 terror attack in Westminster, at the National Police Memorial in Westminster, central London on March 23, 2017.

A man places a floral tribute near a police cordon in Westminster in central London on March 23, 2017.

A police officer lays down flowers from members of the public in London on March 23, 2017.

Bouquets of flowers are left in tribute at the end of Westminster Bridge by the Houses of Parliament in London on March 23, 2017.

Metropolitan Police Service Acting Commissioner Craig Mackey (R) salutes during a minute of silence for their fallen officer, PC Keith Palmer, outside New Scotland Yard in London on March 23, 2017. Scotland Yard said that police have made seven arrests in raids carried out over night in Birmingham London and elsewhere in the country after the terror attack in the Westminister Palace grounds and on Westminster Bridge on March 22. 2017 leaving four people dead, including the attacker, and 29 people injured.

Security services staff pick through debris including a car number plate left following the March 22 terror attack on Westminster Bridge in central London on March 23, 2017.

In a still image taken from footage broadcast by the UK Parliamentary Recording Unit (PRU) on March 23, 2017, shows members of parliament standing for a moment of silence. Britain's parliament reopened on Thursday after an attacker sowed terror in the heart of Westminster. Sombre-looking lawmakers in a packed House of Commons chamber bowed their heads and police officers also marked the silence standing outside the headquarters of London's Metropolitan Police nearby.

A police security cordon remains around the Houses of Parliament on March 23, 2017, in London.

A bunch of roses lays at the Metropolitan Police headquarters at New Scotland Yard in central London on March 23, 2017 during a moment of silence.

A Union flag flies at half mast at the Houses of Parliament on March 23, 2017.

Conservative Member of Parliament Tobias Ellwood, center, helps emergency services attend to an injured person outside the Houses of Parliament in London.

A policeman points a gun at a man on the ground as emergency services attend the scene outside the Palace of Westminster, London.

In this image taken from video, police officers gather around a car adjacent to Houses of Parliament in London.

An video grab obtained from the Twitter account of Polish politician and journalist Radosaw Sikorski, shows a man on the ground receiving assistance on Westminster Bridge after a shooting incident in London.

Armed police push people back following a shooting incident outside the Houses of Parliament in London.

Armed police are seen outside the the Houses of Parliament in London.

A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament in London.

A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament on in London, England.

A member of the public is taken away for treatment by emergency services medic near Westminster Bridge and the Houses of Parliament in London.

A member of the public is treated by emergency services near Westminster Bridge and the Houses of Parliament in London.

Pedestrians react following a suspected terror attack outside parliament in London.

A police officer is led away by a colleague at the scene outside the Palace of Westminster in London.

Police officers gather near the Houses of Parliament in London.

Police secure the area on the south side of Westminster Bridge close to the Houses of Parliament in London. The leader of Britain's House of Commons says a man has been shot by police at Parliament. David Liddington also said there were "reports of further violent incidents in the vicinity." London's police said officers had been called to a firearms incident on Westminster Bridge, near the parliament.

Emergency services staff provide medical attention close to the Houses of Parliament in London.

People leave after being evacuated from the Houses of Parliament in central London.

People leave after being evacuated from the Houses of Parliament in central London.

A police officer stops traffic as the car of British Prime Minister Theresa May is driven away from the Houses of Parliament in central London on March 22, 2017 during an emergency incident.

An armed police officer guards inside a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident.

Armed police officers enter the Houses of Parliament in London after a reported shooting.

An armed police officer stands on Parliament Square outside of the Houses of Parliament in London after reported shooting.

A police officer sets up a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident.

Armed police officers guard at a police cordon outside the Houses of Parliament in central London on March 22, 2017 during an emergency incident.

Assistant Commissioner, Mark Rowley of the Metropolitan Police makes a statement outside of New Scotland Yard in London.

Police boats pass the London Eye as they patrol on the River Thames, near to the Houses of Parliament in London.