India's Modi declares 21-day national lockdown to fight virus

India's 1.3 billion people will go under "total lockdown" for 21 days to combat the spread of the coronavirus pandemic, Prime Minister Narendra Modi said Tuesday.

"From 12 midnight today (1830 GMT Tuesday), the entire country will be in lockdown, total lockdown," Modi said in a national television address to the world's second most-populous nation.

"To save India, to save its every citizen, you, your family... every street, every neighbourhood is being put under lockdown."

India has lagged behind other nations in the number of COVID-19 cases, but there has been a sharp increase in recent days to 519 infections, including 10 deaths, according to the government.

A raft of lockdown measures has been brought in by individual states -- including sealing borders and restricting movement to only essential services -- to try and prevent an explosion of cases that could overwhelm the fragile public health system.

Modi warned that Indians had to observe the lockdown if they wanted to stop the spread of the deadly virus.

"This is a curfew... We will have to pay economic cost of this, but to save every family member, this is the responsibility of everyone -- the biggest priority," the prime minister added.

"If these 21 days are not managed, the country and your family will go back 21 years... I am not saying this as your prime minister, I am saying it as your fellow citizen, family member."

The South Asian nation has already banned incoming international flights for a week from Sunday, and grounded domestic flights and shut sea and river ports.

Indian Railways -- one of the world's biggest networks and carrying more than 20 million passengers daily -- has cancelled all services except suburban and goods trains.