London police report major arrests in attack probe

On Thursday, police identified the attacker as Khalid Masood, a 52-year-old British citizen who had a criminal record and went by other aliases.

"We've seized 2,700 items from these searches, including massive amounts of computer data for us to work through", Rowley said, adding that contact had been made with 3,500 witnesses.

At least 50 people were hurt in the London attack, thought to have been carried out by a "lone wolf" attacker known as Khalid Masood, though Islamic State has claimed responsibility. "There might be people out there who did have concerns about Masood but did not feel comfortable for whatever reason in passing those concerns to us", he said.

Masood ran over dozens of pedestrians and tourists on Westminster Bridge on Wednesday afternoon before crashing his vehicle into parliament, where he managed to stab a police officer before being shot dead.

Irishwoman injured Among the injured was an Irishwoman who was being treated in hospital for "non-life-threatening injuries".

The two dead pedestrians have been named as Aysha Frade, a London college administrator in her 40s, and Kurt Cochran, an American tourist in his 50s.

Six people arrested after the attack on Westminster have been released, while four are still in custody, Scotland Yard says.

Meanwhile, the police arrested eight people and were being investigated "on suspicion of preparation of terrorist acts", the police said in a statement.

Authorities identified Masood, a 52-year-old Briton, as the man who mowed down pedestrians and stabbed a policeman to death outside Parliament in London, saying he had a long criminal record and once was investigated for extremism - but was not now on a terrorism watch list.

"Our investigation focuses on understanding his motivation, his operation and his associates", Mr Rowley said.

Armed with two large knives, he jumped out of the auto after smashing it into the railings encircling the Palace of Westminster, fatally stabbing Pc Palmer as he entered the grounds.

Born in Kent, Masood had been living in England's West Midlands region - where Birmingham is located - and had previous convictions, but not for terrorism offenses, police said.

"To that end in our continuing investigation and ongoing covert activity we have made two further significant arrests overnight", he said.

Westminster attacker Khalid Masood was using the messaging service WhatsApp around two minutes before he ploughed his auto into innocent pedestrians, sparking fears he may have been guided by an Isis mastermind. The Metropolitan Police said the incident was a terrorist attack.

On Friday, the Saudi Arabian government confirmed that Masood worked in the country as an English teacher for two one-year periods between November 2005 and March 2008.

Masood was then shot by armed officers.

Prime minister Theresa May told MPs on Thursday that Masood had come to the attention of MI5 a number of years ago as a "peripheral figure" in violent extremism, but there was no intelligence about his plan to attack parliament.

  • Leroy Wright