Police are cracking down on a disturbing trend in high-value robberies which have hit two victims in the borough.

Met officers believe there is a link between a series of 12 robberies, dating from August last year. It is believed all the victims were followed as they drove home from central London via Swiss Cottage.

On Thursday last week, a 45-year-old housewife from Middleway, Hampstead Garden Suburb, was targeted after she pulled up in her driveway. Two men opened the driver's door and took £9,350 worth of goods, including the victim's wedding ring, handbag and purse before making off towards Thornton Way.

Both suspects are described as black males, aged 20, in dark clothing. One had black, shoulder length hair and dark jeans.

The second incident took place at 1.05am on April 30. The victims, a 54-year-old housewife and her husband, pulled up outside their home in Freston Gardens, Cockfosters. The woman was approached by three suspects, one of whom grabbed at her £14,000 necklace. They ran off empty-handed towards Cat Hill.

Two of the suspects are described as black males, 20-years-old, 6ft tall with shaved heads, wearing dark jeans and t-shirts. The third is described as a black male, 20-years-old, 5ft 8ins tall with dark jeans and a green woollen hat.

Police are advising residents to be vigilant and dial 999 if they see anything suspicious. Witnesses should call Detective Sergeant Mandy Thornhill on 020 8733 4535.