India said on Saturday it was planning to turn some railway carriages into isolation wards for patients with coronavirus, as authorities scrambled to prepare the country's health infrastructure for an expected surge in cases.

Prime Minister Narendra Modi asked the country's 1.3 billion people this week to stay indoors for three weeks in the world's biggest lockdown, seeking to curb the spread of the virus. India's network of trains, the country's lifeblood, has been idled.

One train carriage has been turned into a prototype quarantine facility, state-owned Indian Railways said in a statement on Saturday.

Once they get clearance, the plan is for each of India's railway zones to convert 10 carriages into such wards every week, the company added. Indian Railways has 16 zones, according to its website.

"Railways will offer clean, sanitised & hygienic surroundings for the patients to comfortably recover," tweeted railways minister Piyush Goyal, who did not specify how many people could be cared for in each carriage.

India has reported 918 confirmed cases, including 19 deaths.

The lockdown measures are taking a huge toll on India's poor, including millions of migrant laborers whose jobs in cities have vanished. Many are now walking back to their villages or crowded at bus stations in the hope of finding rare transport, raising fears they will unintentionally spread the virus across the country.

On Saturday, a migrant worker, who set out from New Delhi on a 270-kilometer-long walk to his hometown in the central Indian state of Madhya Pradesh, collapsed and died, a police official said.

India's home ministry said in a statement on Saturday it was advising states to provide food and shelter to migrants at relief camps alongside highways.

To date, the number of coronavirus cases in South Asia has risen to 2,648, including 39 deaths. Sri Lanka reported its first coronavirus death on Saturday, a 65-year-old diabetic tour guide.

While the toll in South Asia remains low overall, there are fears it could swell given the region's poor health services and population density.

In Pakistan, police on Saturday arrested 38 prayer leaders and mosque officials for violating a ban on congregational prayers even as cases swelled to over 1,400 in the country.

A plane carrying relief assistance and eight doctors from key ally China landed in Islamabad on Saturday, a Pakistani foreign ministry statement said.

"(They will) advise our health care specialists in the light of their experience and success in battling COVID-19 in China," the statement read. China has already given Islamabad testing kits, masks, protective gear and other medical equipment.

In Nepal, more than 600 European tourists were evacuated on chartered flights on Saturday, authorities said, but thousands more are still waiting to be brought home by their countries.

"This will leave between 8,000 and 10,000 tourists still stranded due to lockdown in Nepal," said Dhananjay Regmi, the chief of Nepal's tourism board.