QUETTA - Unknown armed persons on Friday blew up railway track at Mach area which caused suspension of rail service to other parts of the country for several hours. Reportedly, unknown persons had planted explosive device with railway track in Mach area. The explosive went off blowing up two feet of railway track. Rail service remained suspended for about five hours between Quetta and other parts of country. However, the damaged portion of the track was repaired by railway engineers and workers and rail traffic was restored after five hours.