New Delhi recorded fewer than 1,000 coronavirus cases for the first time in seven weeks on Tuesday, even as more Indian states imposed restrictions to halt the spread of the pandemic.

India last week became the third country after the United States and Brazil to hit one million cases but many experts say that with testing rates low, the true number could be much higher.

More than 28,000 people have died, with the western state of Maharashtra, home to Mumbai and its teeming slums, suffering the highest death toll followed by the national capital Delhi and Tamil Nadu in the south.

Prime Minister Narendra Modi's government imposed one of the world's strictest lockdowns in late March, but it has been steadily eased in recent months to lessen the devastating economic impact.

But, independently from the federal government, individual states have been tightening restrictions as case numbers have soared -- including in Bangalore, Bihar and parts of Kerala and Tamil Nadu.

On Monday authorities in the eastern state of West Bengal, home to about 90 million people, imposed a strict lockdown two days a week beginning Thursday.

"The state government feels that the efforts to break the chain of COVID-19 spread have to be initiated in a strong manner," the state's home secretary Alapan Bandopadhyay said.

All government and private offices will be closed and there will be no public transport. Private vehicles will be allowed for essential needs only.

The small northeastern state of Sikkim, bordering Tibet, on Monday also ordered a lockdown until July 27.

Delhi has offered a rare piece of good news, however, with the crisis easing since June, when hospitals and morgues in the sprawling megacity of 20 million people appeared close to collapse.

Monday's count of 954 new infections in the city marked the first time the daily tally was under 1,000 in 49 days, and was down from a peak of almost 4,000 in late June.