The latest volume of the popular Harry Potter children's book series - about a boy wizard - has gone on sale in Britain.

Bookstores across the country opened their doors at one minute past midnight, admitting thousands of child and adult fans who lined up outside for hours to buy the sixth book in the series Harry Potter And The Half-Blood Prince

Similar dramatic midnight opening-day events are planned in cities around the world.

Since 1997, the series has sold some 270 million copies in 62 languages, making author J.K. Rowling the richest woman in Britain with an estimated fortune of $1 billion.

But the financial and popular success of the series has not come without criticism. The future Pope Benedict expressed concern over the series in 2003, writing that the books "erode Christianity in the soul" of young people.

Some information for this story provided by AP and AFP.