KARACHI: The Muttahida Qaumi Movement (MQM) is observing a day of mourning against the killing of its workers and sympathizers today (Thursday). MQM Coordination Committee has appealed to the businessman and transporters to keep their businesses closed and vehicles off the roads. Responding to the MQM's strike call the Sindh, Technical board has cancelled all the exams scheduled for Thursday. A sit-in was staged outside the Chief Minister House against the killing of three MQM sympathizers whose bodies were found in Memon Goath area of Malir on Wednesday. A large number of MQM workers and leaders attended the protest which continued till late night on Wednesday. The participants warned the government that a sit-in would be staged after the Soyem of the deceased if the killers were not arrested. They demanded of the Sindh government to distance itself from criminals and arrest gangsters.