Fearless, fanatical and feminine. Women have proven to be some of the most ruthlessly effective of bombers and hijackers. Bridget Kendall investigates their motivation.

From Russia's 19th century Nihilists to contemporary Sri Lanka and the Middle East women have played central roles in terror organisations. Attacks planned or executed by women certainly attract more attention and seem to inspire a different kind of fear.

Why are we still shocked by women who bomb, kidnap and kill? Why are they so effective? How can women be dissuaded from joining terrorist organisations? BBC Diplomatic Correspondent Bridget Kendall investigates the motives that drive these women and considers the response of the media and the public to those who have planted bombs, hijacked planes and killed innocents in their quest for political change.