Some thoughts:
1. JUI is a religious party and they are known to have a soft corner for Taliban. I highly doubt that this is the work of Sunni religious extremists. It seems more probable that the perpetrators are the secular Baloch separatists, or people in the pay of NDS.
2.
@BHarwana is creating an improbable equivalence. Its not a surprise since his sympathies are clearly with Iranian sectarian Mullah regime.
3. There is a chance that this could be a pro-active approach from Iran. They have shown displeasure with Pakistan. They also have paid agents in Pakistan. We do know that they actively recruit Pakistanis to fight as part of Iranian-sponsored militias in Syria.
4. Iranian FM M. Javed Zarif made an unannounced visit to Pakistan last Wednesday and two days later visited Kabul on Sunday.
5. The dots seem to connect Iranian regime with Kabul (non)government. Only evidence missing is the one that connects India to this mix. Many can imagine that Indians may already be involved. I shall wait for credible information at this juncture.
6. In the early 90s the sectarian tensions in certain parts of Pakistan were very high. Iran had taken a decidedly anti-Pakistan stance since 1994, when it torpedoed anti-India resolution over Kashmir in Geneva. Pakistan seems to have written off friendly relations with Iran since then. The hardening of attitude could only have been strengthened when Khatami government outed involvement of Dr. Abdul Qadeer in Iranian attempts to enrich Uranium.
7. If Pakistan continues its policy of supporting the GCC countries, we must be ready for reaction at home. Anti-Iranian organizations trying to operate from within Pakistan could conceivably be countered by secular Baloch separatist organizations. Where money and resources required would come from is anybody's guess. But Iran and Afghanistan can not be ruled out.
8. Sections within Afghan government might be growing in paranoia, since it increasingly looks clear that some sort of settlement with Taliban has to be made. Americans can not continue to support the current set-up. Taliban are not in the mood to listen and consequently pressure on Pakistan seems to be an option topmost on some minds.
I just hope Pakistani policy-makers knew what they were doing when they decided to side with GCC in the regional tussle. The future does not look good in my view.