This is another despicable act. Unfortunately being a christian in Pakistan is synonymous with being a sweeper and these extremists don't consider/treat them as human-beings. This is nothing but khulli badmaashi and must be condemned.
On a separate note I have yet to come across a mullah or maulvi who made a d'ua for all of mankind and not just muslims during the traditional Friday or Eid prayers. They always only pray for Islam and Muslims. I asked one mullah about this ((after all isn't the rest of mankind (however mis-guided they are from our perspective...) His creation too)) and not surprisngly he had no answer. Such narrow-minded thinking is drummed into us from a very young age and it's no surprise then that some of us grow up with very extreme/intolerant views about 'others'. Why can't they say a prayer, something like, "Oh Allah we are all so grateful to you that you gave us Islam......have your mercy on all human-beings and give guidance to us and the non-muslims amongst us."