Sadly, this has been happening for a long time now. Pushtun people have turned Faisal Mosque as well as other parts of Islamabad and Pindi into a no-go area for families.
Sindhi nationalism never raises the questions of feudalism, underdevelopment, decreasing literacy, corruption, or anything to do with the actual state of Sindh. It only rears its head when the question of Karachi's rights comes up. That should tell you what it actually is.