A、the historic hatred between Sunni and Shiite Muslims B、there are sectarian terrorists among both Sunni and Shiite Muslims C、Su

A bomb has exploded at a Shiite Mosque in Karachi, Pakistan, killing at least 16 people and wounding more than 30 others. VOA’s Michael Kitchen reports from the Pakistani capital Islamabad.
   Police say a bomb planted in a main Shiite mosque in Pakistan’s largest city was detonated during Monday evening prayers. The blast sparked rioting in the neighborhood around the house of worship, marking the second straight day of civil unrest. On Sunday, citywide rioting erupted following the assassination of a well respected Sunni Muslim cleric. Pakistani Interior Secretary Abdullah says the mosque bombing is likely a response by Sunni extremists to the assassination.  While Pakistan’s majority Sunni and minority Shiite Muslims normally enjoy good relations, extremists on both sides continue to commit acts of sectarian terrorism against each other’s populations. Michael Kitchen, VOA news, Islamabad.