Mobile phones have also been taken as crooks swoop on unsuspecting pedestrians and wrench their property out of their hands.

The robbers are using mopeds and mini-mopeds to carry out the attacks, most of which have happened between 11am and 3pm.

In the latest incident, a yob on a bicycle targeted an elderly couple walking along Mary Armyne Road, in Orton Longueville, on Wednesday, August 6.

The robber tried to snatch the woman's handbag, but she bravely managed to cling on to it, and he rode off empty-handed.

Police are now looking for witnesses who may have seen the youth, who is described as aged 14 or 15 and was wearing a dark blue tracksuit with white piping.

This is the latest in a string of more than eight robberies in the last two weeks across Peterborough.

July 28 – handbag snatch by cyclist in Pittneys, Paston.

July 29 – handbag snatch in Saville Road, Westwood.

July 30 – handbag snatch in Weatherthorn, Orton Longueville.

July 30 – attempted handbag snatch in The Village, Orton Longueville.

August 2 – attempted handbag snatch in Larch Grove, Dogsthorpe.

August 3 – Mobile phone snatch in Bretton Way, Bretton.

August 3 – Mobile phone snatch in Lincoln Road.

Today, police urged residents across the city to be vigilant and if possible not to walk on their own, and to choose a busier route with more people around.

Inspector Matt Snow said: "If you use routes regularly where there have been attacks, keep any valuables out of view if possible, put your handbag over your body so it's a lot harder to grab, or don't even take them out.

"In Orton, we have stepped up our cycle patrols, making them more visible, and we have been targeting suspects we believe may have had involvement."

Police have also issued a new description of the man they want in connection with a series of attacks in Orton, one of which put a victim in hospital for two days.

The woman was attacked at 10am on August 3 as she was walking past the Gloucester Centre, in Morpeth Close, Orton Longueville.

The youth on a moped grabbed her handbag from her shoulder and as she tried desperately to hold on to the strap, he viciously knocked her over and dragged her along the ground for several seconds.

The man is described as having olive skin and wearing a dark coloured hoodie.

In another incident, he wore a helmet and leathers.

The moped has been described as being either mini or very small and loud. no colour has been mentioned.

Police in Orton have linked three of the incidents in their area, and have charged one man with theft.