People with UPVC doors are being advised to take extra care in locking them after four homes in Hertsmere were broken into in two weeks.

Between April 7 and 19, a number of items including cars, ladies handbags, video games and MP3 players were stolen from houses with UPVC doors, in some cases while the owners of the property were asleep.

Hertfordshire Constabulary is asking residents to ensure all doors are double-locked. Detective Inspector Mike Marren explained that lifting up the handle once the door is closed does not automatically lock the door.

He said: "We believe that a burglar is able to tell from moving the handle on the outside whether the door has been key locked or not. Those which are locked present a much more difficult entry."

"Also store the keys away from the front door so that it's impossible for a burglar to put an implement through the letter box to access it."

To learn more about crime prevention, visit www.herts.police.uk