The aircraft departed from Islamabad Airport Runway 28L at 4:17 PM and landed on Islamabad Airport Runway 28L at 4:57 PM i.e 40 minutes after takeoff. Around 4:32 PM i.e. about 15 minutes after takeoff when the aircraft was flying at altitude of 28,000 feet it initiated U-turn towards Islamabad.
Flight PF124 was scheduled to leave Islamabad at 4:00 PM.

Source: flightradar24.com
Later, the aircraft left Islamabad at 6:01 PM to resume flight PF124 to Karachi.

Source: flightradar24.com
Abbas