Harry Potter mania sweep the planet

Ending months of hype, and elaborate measures to prevent details of the boy wizard's latest adventures leaking out, "Harry Potter and the Half-Blood Prince" hit the shelves at one minute past midnight London time.

Children from around the world descended on the Scottish city of Edinburgh, where Potter author J.K. Rowling read from the latest book the moment the deadline passed.

"I am excited," she said on her way into a dramatically lit Edinburgh Castle. "You get a lot of answers in this book."

On Sunday, 70 aspiring cub reporters representing international newspapers and broadcasters will hold a press conference with Rowling.

In Australia, thousands of "Pottermaniacs," some carrying live snakes, besieged bookstores in the outback, in the country's snowfields and along its beaches.

Before dawn on Saturday morning in Sydney more than 1,000 fans boarded a special train called the Gleewarts Express, which took them to a secret location outside the city where they received their copies.

Dressed as their favourite characters, fans poured over their copies in a cold and eerie country mist.

Kate Suthers flew out from Britain to take the train.

"I did it three years ago and it was fantastic," said Suthers.

Minutes after its release in Sydney's central business district, non-magic "muggles" and wizards, young and old, scurried down empty streets clutching their precious books.

Some dressed as witches, caps flapping, stood reading as they waited for a bus. Others did not even get out of the bookstore.

"There are so many unanswered questions," said Elizabeth Mackay, 15, as she read the first few pages inside a shop. "Its so exciting, something has happened, a bridge has collapsed."

In Britain, thousands of parents and children queued outside bookshops.

"Every book just gets bigger and bigger," said David Roche of Waterstone's book retailer in central London.

A Portuguese girl called Carlotta was the first in the chain's flagship store to buy the new book.