Protests have been taking place for the past two weeks.
Sit-in demonstrations have been taking place in different parts of Balochistan including Quetta city.
Supporters of the four-party alliance continued the sit-in outside the office of the Quetta district returning officer, Dawn News reported.
Demonstrators even set up a roadside camp to continue their protest.
Traffic was disrupted in certain parts of Balochistan owing to the protest.