LONDON, Feb. 7 (Xinhua) -- British Prime Minister Tony Blair on Wednesday expressed his sympathy for the victims of a series of parcel explosions in the past five days.

    When asked about the latest blast at his weekly question-and-answer session in the House of Commons, Blair said the investigation on the attacks is under way.

    Blair made the remarks after the police in Kent, southeast England, confirmed on Wednesday that a letter bomb exploded on Saturday.

    The letter bomb was sent to the private address of a 53-year-old man in Folkstone, Sky News Television reported, He was slightly injured in the blast.

    Sky News reported that seven postal devices had been received in last three weeks and six people injured in the parcel bomb explosions.

    Earlier, Home Secretary John Reid said that a series of parcel bomb attacks was worrying, and he was being kept fully briefed on the investigations.

    On Wednesday morning, a female member of staff was injured in a parcel bomb explosion in Swansea, Wales. The latest blast happened in the post room of the Driver and Vehicle Licensing Agency.

    Police are investigating links to the spate of parcel bombs sent to organizations involved in running Britain's roads.

    On Tuesday, two men suffered blast wounds on their hands and upper bodies in a package explosion at the offices of an accountancy firm linked to Speed Check Services in Wokingham, Berkshire, south England.

    On Monday, a female worker was hurt by a device at the Offices of Capita in central London, which runs London's congestion charge system.

    The attacks appear to have confirmed fears that an enraged motorist is mounting a daily parcel bomb campaign.