India's colossal passenger railway system has come to a halt as officials take emergency measures to keep the coronavirus pandemic from spreading in the country of 1.3 billion.

The railway system is often described as India's lifeline, transporting 23 million people across the vast subcontinent each day, some 8.4 billion passengers each year.

India's rail network, the world's fourth-largest, operates more than 12,100 trains carrying passengers and cargo along 67,415 kilometres (41,890 miles) of track. With more than 1.2 million employees, it is the country's largest employer.

The New Delhi Railway Station, usually populated 24 hours a day with railway staff, shops selling snacks and newspapers, passengers crammed into waiting rooms and indigent people sleeping on the platform, was barren.

Prime Minister Narendra Modi announced a nationwide "total lockdown" for 21 days starting Wednesday, ordering one-fifth of the world's population to stay home.

Health officials have reported 512 cases of COVID-19, the respiratory disease caused by the new coronavirus, and at least nine deaths.