Officers from the London police's counter-terrorism command attended six addresses in London and one address in Luton, the BBC news reported.

The men were arrested for conspiracy to commit fraud and money laundering and the woman for money laundering.
The fraud involves elderly people being cold-called, police said.

Officers said "unsuspecting, vulnerable" elderly victims were called on their home phone by someone impersonating a police officer.

Three men aged 23, one of 21 and another of 28, along with a woman aged 32, were all arrested at addresses in north London while a 38-year-old man was arrested in Luton.