Bomb defused outside Potter book launch in Pakistan

Pakistan police say they defused a bomb outside a shopping centre where the latest Harry Potter book was scheduled to be launched.

"Police have foiled an attempt to blow up a car bomb by remote control outside the Pak Towers and defused 10 kilograms of explosives in a stolen car," Karachi police investigation chief Manzoor Mughal said.

"Had it exploded it would have caused a huge loss of lives," Mr Mughal said.

The launch of Harry Potter and the Deathly Hallows in the early hours of Saturday (9:01am AEST) had been postponed until later in the day at a book shop in the Karachi shopping centre.

"There were several hundred people inside Pak Towers (shopping centre) at the time we received the call from an unknown person that a bomb was about to explode," Mr Mughal said.