The Karachi-based ATR 42-500 aircraft registration AP-BHI has been grounded at Karachi Airport for maintenance checks/work. It had arrived in Karachi at 4:41 PM as flight PK502 from Turbat on September 7. It's expected to resume flying from September 11.
PIA ATR flights from Karachi including flights between Karachi and Sukkur have been cancelled due to grounding of ATR 42-500 aircraft registration AP-BHI.

Source: flightradar24.com
The other currently active ATR in PIA fleet i.e. ATR 42-500 aircraft registration AP-BHH is based at Islamabad and in recent days performed flights on routes including:
Islamabad-Gilgit-Islamabad
Islamabad-Chitral-Islamabad
Islamabad-Multan-Islamabad
Islamabad-Sukkur-Islamabad
https://www.flightradar24.com/data/aircraft/ap-bhh
Abbas