A man has been arrested in connection with a series of letter bomb attacks, including two in Oxfordshire, police said today.

The man was arrested in Cambridge by detectives investigating the attacks on businesses linked to forensic science laboratories and traffic enforcement.

A total of seven letter bombs have been sent across Britain over the last month.

In each of the recent attacks, the bombs have been home-made devices in A5 padded envelopes. At least two contained glass.

The first three, last month, were directed at forensic science laboratories in the West Midlands and Oxfordshire.

On Thursday, January 18, aan explosion injured a woman at Orchid Cellmark, a firm based at Abingdon Business Park, which specialises in DNA work The same day, police were called to LGC Forensics, in Culham, to carry out a controlled explosion. No-one was hurt.

They were followed by an attack on February 3 on a house in Folkestone, Kent, which is used as a business address.

The following week, three letter bombs exploded on consecutive days at motoring-related offices in London, Wokingham, Berkshire and Swansea.

They included the Driver and Vehicle Licensing Agency in Swansea and the offices of the company which runs London's congestion charging system.

At least nine people have been injured in the blasts.