London attack

But the three men failed to provide payment details and the vehicle was not picked up, prompting them to use a smaller van from a DIY store instead.

The men drove into pedestrians on the bridge before stabbing people in Borough Market seven days ago.

Police said the men tied 12in (30cm) pink ceramic knives to their wrists and had petrol bombs in the van.

Eight people were killed and dozens more were injured in the attack, which began shortly before 22:00 BST on 3 June.

A 30-year-old man previously arrested in Birmingham "on suspicion of preparation of terrorist acts" was freed Saturday, the police said in a statement.

In addition, 11 others who were previously arrested in connection with the attack investigation have all been released with no further action, police said.

The attacker, Khalid Masood, 52, was shot dead by a police firearms officer at the scene of the March 22 incident.

Following last week's terrorist attack in London, the UK government is accusing technology firms to give terrorists "a place to hide," saying Intelligence agencies must have access to encrypted messaging applications such as WhatsApp to prevent such attacks.

Janet Ajao said she had "shed many tears for the people caught up in this horrendous incident".

Masood killed three people when he drove a car into pedestrians last Wednesday. He then fatally stabbed a police officer before being shot dead.

Meanwhile, police say no evidence has been found of links between Masood and so-called Islamic State or al-Qaeda.

Mrs Ajao, from Trelech in Carmarthenshire, said: "I wish to make it absolutely clear, so there can be no doubt, I do not condone his actions nor support the beliefs he held that led to him committing this atrocity.

Khalid Masood was active on the encryption messaging service WhatsApp two minutes before he started his attack Wednesday on Westminster Bridge, but no evidence has emerged to show he was communicating with ISIS at any point, the official told CNN.

Investigators are looking into communications he had with individuals leading up to the attack that left four dead, including a police officer, the official added.

Khalid Masood was active on the encryption messaging service WhatsApp two minutes before he started his attack Wednesday on Westminster Bridge, but no evidence has emerged to show he was communicating with ISIS at any point, the official told CNN.

Investigators are looking into communications he had with individuals leading up to the attack that left four dead, including a police officer, the official added.

Organizer Muddassar Ahmed was inside Parliament when attacker Khalid Masood drove his car into pedestrians on Westminster Bridge, leaving three dead, and stabbed to death an unarmed police officer outside Parliament.

"I saw all the carnage before me," Ahmed told CNN. "We were trapped there for about four hours."

He said that the feelings of panic and fear he had in his spot of relative safety made him wonder about how the victims felt, and he decided, on returning home around 1 a.m., to make a call for donations for them.

Officers investigating Wednesday's attack said they wanted to hear about "associates and places he visited".

The fourth victim has been named as Leslie Rhodes, 75, from Streatham in south London - one of three killed by Masood's car on Westminster Bridge.

Masood then stabbed PC Keith Palmer near Parliament. Police said they have made two more "significant arrests".

Fifty people were injured in the attack, with 31 receiving hospital treatment. Two are in a critical condition; one has life-threatening injuries.

The fourth victim, a 75-year-old man, died Thursday night after his life support was withdrawn at a hospital where he had been receiving treatment, according to London's Metropolitan Police.

Arrests were made in London and Birmingham, while homes were also searched in Brighton and Carmarthenshire, in South Wales.

Police said the addresses were "linked to the investigation" of Wednesday's attack, carried out by 52-year-old British man Khalid Masood.

Masood, 52, was born as Adrian Elms in Kent and was shot dead by police. He had not been the subject of any current police investigations.

PC Keith Palmer, 48, Aysha Frade and US tourist Kurt Cochran, 54, were killed on Wednesday, while a 75-year-old man died on Thursday evening.

The so-called Islamic State group has said it was behind the attack.