The police are investigating a spate of burglaries in Sliema over the past few weeks, with the culprits believed to be a gang of organised criminals using sophisticated tools such as ‘bump keys’.

Police sources said that although there was no cause for alarm, people should be on the lookout for anything unusual happening in their street.

The robbers are targeting apartments rather than houses, especially those without alarm systems or closed circuit camera surveillance.

The latest thefts took place on Friday evening when robbers targeted two apartments in the same block. Police sources said after the thieves entered the flats they placed a pair of socks from the apartments on their shoes to leave no traces whatsoever and then removed them on their way out.

Since the beginning of the month there have been thefts in Cathedral Street, Graham Street, Tigné, Tower Road and Hughes Hallett Street.

There was a similar spate of thefts in Sliema and St Julian’s last summer, with a pattern that involved professional thieves who broke into houses through main doors that were also equipped with ‘super locks’, a multi-lock system.

Residents in St Julian’s and Sliema had reported “suspicious” signs scribbled on their intercoms – a method used abroad to target specific residences.