London - British police arrested seven people in armed raids Thursday linked to the deadly "Islamist-related" attacks the day before on the symbol of the country's democracy. Britain's top anti-terror officer Mark Rowley also said police have revised down the number of victims from Wednesday's rampage to three from four. Some 40 people were wounded. "We have searched six addresses and made seven arrests," Britain's top anti-terror officer Mark Rowley told reporters in London. He said the raids included locations in London and the central city of Birmingham.The attack unfolded on Wednesday across Westminster Bridge in the shadow of Big Ben, a towering landmark that draws tourists by the millions and stands over Britain's Houses of Parliament - the very image of London.The attacker's car struck pedestrians on the bridge before crashing into the railings surrounding the heavily guarded Houses of Parliament, sowing first shock then panic in the seat of British power.The assailant then ran through the gates brandishing a knife and stabbed a 48-year-old policeman to death before being shot dead by another officer.