Karachi blast: 'Worrying rise in sectarian violence'
At least 45 people have been killed by a bomb explosion in the Pakistani city of Karachi, according to local police.
The blast in the mainly Shia Muslim area of Abbas Town destroyed several buildings and set others on fire. Some reports spoke of a second explosion.
The BBC's Mike Wooldridge said that the attack would be "deeply worrying for the government" as there has been a significant rise in sectarian violence in parts of Pakistan.