At least three persons were killed and 21 others including women and children injured when unidentified armed men opened fire at Quetta Express here in Mach on Sunday. According to police, unknown miscreants sitting in ambush started indiscriminate firing at Rawalpindi bound Quetta Express when it reached Sirrey Bolan are of Mach. Three persons identified as Majeed, Rahimdad and Maqbool were killed in the firing by the miscreants while 21 others including woman and children sustained injuries. The injured were shifted to hospital for treatment. The three people killed in the firing incident were stated to be hailing from Bahawalpur and Vehari districts of Punjab. Police and Frontier Constabulary (FC) cordoned off the area after the incident and launched search operation but no arrest has been made. Meanwhile people have expressed their grave concern over violent incidents in Balochistan where Punjabi speaking people are being targeted particularly. They were of the view that law enforcement authorities were not taking prompt action against the criminal elements due to which people are suffering.