The bombs were attached to motorcycles and exploded at crowded marketplace in the majority-Shiite Ancholi area of Karachi late Friday night.
The Tehreek-e-Taliban Pakistan (TTP) spokesman claimed responsibility in telephone calls to media persons.
Shahid said that these attacks were reaction to the sectarian attacks in the city of Rawalpindi on November 25 which killed 11 people and the US drone attack on a religious school on November 21 killing six students and teachers.
