According to details, the passenger involved in the incident had earlier misbehaved with check-in staff at Quetta Airport. After boarding the aircraft she exhibited bad behavior that was reported by the cabin crew to the cockpit crew before takeoff.
Airports Security Force (ASF) was called to off-load the rowdy passenger who was traveling with her father. During the off-loading process the flight attendant was punched in the face by the female passenger.
On March 18, Serene Air Boeing 737-800 aircraft registration AP-BNA left Quetta at 6:39 PM as flight ER540 to Islamabad.

Source: flightradar24.com
Abbas