A Railway Protection Force (RPF) constable on Monday shot dead 4 persons on board a running train near Palghar railway station in Maharashtra, an official said.
The constable fired from his automatic weapon, killing an RPF Assistant Sub Inspector and three other passengers of the Jaipur-Mumbai Central Express shortly after 5 am, the official said.
Palghar is around 100 km from Mumbai.
Chetan Kumar Choudhary opened fire on his escort duty incharge ASI Tika Ram Meena in the running train, the official said.
After killing his senior, the constable went to another bogie and shot dead three passengers, the official added.
The constable was caught by police at Mira Road with the help of Government Railway Police and RPF officials.