The two police constables, who were traveling on a train, were shot dead by armed criminals and they freed a criminal from police custody. The incident occurred on Tuesday night on Allahabad- Jaunpur Passenger train near Phulpur of Allahabad distrct. According to police sources, the criminal who was freed was involved in several cases and was being brought back to Nani Jail after being produced in Jaunpur court. Sources said that the incident happened between Ugrensenpur and Phulpur at around 8 pm. The deceased constables were identified as Hari Ram and Dharmendra. According to police, the motive of the attack was only to free the dreaded criminal who was lodged in Naini Central Jail as the miscreants did not touch the two rifles of the constables. DIG Police Brij Bhusan said that a hunt is on to nab the criminals.