British police say they have arrested seven men as part of an investigation into an alleged fraud linked to extremists in Syria.

Counterterrorism officers raided six locations in the London area and detained the seven on Wednesday. The men, aged 21 to 38, were arrested for conspiracy to commit fraud and money-laundering.

Police said the men were being investigated for their alleged part in a large-scale fraud, in which suspects posing as police officers call vulnerable and elderly people at home to obtain their bank account details.

Police arrested two other men in March in connection with similar offenses.