A press release confirming the news read: "Kate decided to add the extra shows in a bid to make sure as many people who wish to see a show can do so.
"This follows massive pre-sale demand from fans who had pre-registered on www.katebush.com; a specific allocation of tickets was reserved for this purpose and these sold-out in 30 minutes."
The 55-year-old pop singer said several years ago that she hoped to return to the concert stage before she becomes "too ancient" to carry it off. She had toured in her 20s but stopped at an early age, later saying it had become physically exhausting.
The singer has largely stayed out of the public eye for decades but has released occasional new material.
Bush's Before the Dawn tour starts on August 26 and runs until October 1.
