Watch out Muggles, Death Eaters attack Trafalgar Square

HARRY Potter fans look away now: this is London being attacked by his enemies the Death Eaters.

The spectacular sequence in which Lord Voldemort's henchmen launch an aerial fusilade on Trafalgar Square and other landmarks including the Millennium Bridge is the centrepiece of Harry Potter And The Half-Blood Prince, the next instalment of the young wizard's adventures.

The image comes from a new trailer which has already become one of the most popular downloads on the internet.

But the airborne assault on London is an invention which does not feature in JK Rowling's original book. It is the first time the series has diverged significantly from the books and will surprise many fans. The trailer also shows the first kiss between Harry and Ginny Weasley, younger sister of his best friend Ron.

The Half-Blood Prince is the second of the series to be directed by British director David Yates.

The film, due to be released on 17 July, will be followed by the final part, Harry Potter And The Deathly Hallows - which will be split into two films. It will be released in 2011, by which time its stars will be well past the ages of their teenage characters.

Daniel Radcliffe, who plays Harry, will be 22, while Emma Watson, who plays Hermione Grainger, will be 21 - although both their characters are 17 in the final book.

The actress, who celebrated her 19th birthday yesterday, will by then have completed much of the degree at Cambridge for which she plans to study.