London Underground is set to roll out high-tech CCTV surveillance software that will automatically alert operators to suspicious behaviour, unattended packages and potential suicide attempts on the capital's Tube system. The move comes as London remains on a high state of alert against a possible terrorist attack following the bombs in Madrid earlier this month.

LU has been trialling the technology at Liverpool Street station during the past two months and is now evaluating the results with a network-wide rollout tipped to follow across the Tube's 6,000 CCTV cameras, which cover 95 per cent of stations.

The Intelligent Pedestrian Surveillance system from Ipsotek compares CCTV footage against pictures of the empty station and alerts operators to strange behaviour such as people loitering or bags that have been left on the platform.

Sergio Velastin, director of research and founder of Ipsotek, said that it cuts down on operator time and costs related to blanket monitoring of all CCTV screens by alerting staff only when there is a potential problem. Privacy groups are concerned about the increasing coverage of monitoring technology such as CCTV. Velastin dismissed privacy concerns over IPS and said the software monitors only behavioural patterns and not the individual.

We have tried very consciously to stay away from facial recognition issues. None of our system is capable of recognising an individual – just behaviour. Then the police can come in and say 'we need to find out who that person is'. It is a balance between being free to do what we wish and being protected.