NEW DELHI, OCT 1: Two persons were killed and more than twenty injured when three explosions rocked the Amritsar-bound Frontier Mail at Sahihabad and Ghaziabad stations tonight, Northern Railway and police sources said.While most of the injured were in coach S-3 (number 96307) and S-4 (number 96274), one passenger was hurt in coach S-6 (92246) and another in general compartment (97433). The general compartment, which was the third from the engine, was almost empty at the time of the blasts, railway sources said.The first explosion took place on the moving train near Sahibabad a little before 2100 hours. Two more explosions occurred in quick succession when the train reached Ghaziabad station. Three coaches of the train were rocked by the blasts. The second explosion took place at 2100 hours and the third at 2112 hours.Northern Railway General Manager S P Mehta and Commissioner of Railway Safety V S Dutta rushed to the spot along with a medical team. Police cordoned off the area following the blasts.