British police arrested a suspect in a series of letter bombs sent to offices linked to traffic enforcement, authorities said Monday.

The man was arrested in Cambridge, England, police said.

On Feb. 5, a woman was injured by an exploding parcel at the head office of Capita Group PLC in London. One of the company's many government contracts is for designing and running a system for enforcing the $16 daily charge imposed on motorists in central London.

Two people were injured Feb. 6 in an explosion at Vantis PLC in Wokingham, 40 miles southwest of London. The accounting company reported the package was addressed to a client. Police said the company's clients include Speed Check Services, which provides traffic monitoring technology.

The next day, three people were treated after a parcel bomb exploded at the headquarters of the Driver and Vehicle Licensing Agency in Swansea, Wales.