A bomb exploded on a bus in Karachi, Pakistan, on Saturday, killing six and wounding 48, eight of whom were reportedly in critical condition. Officials disagree on the location of the bomb, with some saying it was planted on the bus and others claiming it was on a motorcycle and went off as the bus passed by. Pakistan's biggest city and its commercial capital, Karachi has been plagued by violence from attacks by militants and ethnic tensions over the last 10 years.
