Police in England is trying to solve a mysterious case of an animal-rights activist who reportedly sent "letter bombs" to three companies that provide forensic services to police.

A 40-year-old woman working for Orchid Cellmark in Abingdon was hurt Thursday when she opened the explosive letter. Orchid Cellmark spokesman said, "We are shocked to have been targeted in this way and are relieved that our colleague was not seriously injured. We have provided forensic DNA services to the police for 20 years and this is the first time we have experienced anything of this nature."

According to BBC reports, a Chelmsley Wood, Birmingham based company received an A5 jiffy bag containing a firework-type explosive on Thursday afternoon, which had the name of an animal rights campaigner and convicted fire-bomber, who died in 2001.

The Thames Valley Police, investigating the case said another letter was sent to a firm in Culham, near Abingdon, but failed to explode.