India's financial hub Mumbai set to extend coronavirus lockdown

India's financial hub Mumbai is set to extend lockdown measures until at least April 30 as authorities race to expand testing to stem the spread of coronavirus in the city, three senior officials said.

A 21-day nationwide lockdown that prime minister Narendra Modi declared in late March to fight the epidemic is officially set to end on April 14.

But Mumbai, with a population of more than 20 million, has become India's coronavirus epicentre. The metropolis and its suburbs have reported 782 positive cases and 50 deaths, the latest health bulletin said on Wednesday.

"In Mumbai cases are rising too fast. In just 24 hours 100 cases were reported on Tuesday," said a senior state government official, adding that the trend was alarming and at least another two weeks of lockdown were necessary to stop the virus from spreading in one of the world's most densely populated cities.

Mumbai municipal authority and the state government of Maharashtra, of which Mumbai is the capital, both declined to comment.

The state government has yet to announce the extension as it is assessing the situation in satellite city Pune and Nagpur, a commercial hub.

As of Wednesday morning, Maharashtra accounted for 1,078, or more than 20 per cent of India's 5,194 confirmed cases. It has also recorded 64 deaths, or 43 per cent of India's 149 fatalities.

A second senior government official in Mumbai said the "only solution" to deal with the grave public health emergency was to extend the lockdown by two weeks.

Both officials requested anonymity as they were not cleared to discuss the matter with the media.

A federal home ministry official said several state governments, including Maharastra, had proposed an extension of the lockdown, and these requests were being considered by Modi's office.

In April, health officials in Mumbai witnessed a worrying trend of patients who had no initial symptoms but later tested positive, infecting medical staff and forcing hospitals to close partially.

The state government had identified companies to manufacture rapid test kits which could be used in slum districts and government offices to test people with mild symptoms.

"We are thinking to use rapid test kits, but these kits need certification," said Uddhav Thackeray, the state chief minister. "The moment they will be approved and made available, we will start using them."

Thousands of female health workers trained to administer the polio vaccine will be recruited to use the mobile test kits in the next two weeks.