BENGALURU/MUMBAI: India's high-tech hub of Bengaluru will go back into a coronavirus lockdown for a week on Tuesday after a surge of infections, threatening to derail government efforts to revive a stuttering economy.

Places of worship, public transport, government offices and most shops will shut down again from the evening, and people will be confined to their homes, only allowed out for essential needs.

Schools, colleges and restaurants will stay shut, authorities said.

Bengaluru, home to some of the world's biggest IT companies, such as Infosys, had only about 1,000 novel coronavirus cases in mid-June and was seen to have done better than other parts of the India in terms of testing and contact tracing.

But the number has grown to nearly 20,000 as of Monday, which health experts blamed on the lifting of restrictions in June, when Prime Minister Narendra Modi's government, worried about the economy, ended a nationwide lockdown that had thrown millions out of work.

Bengaluru began seeing a surge in infections from late June as both testing and people's movements picked up, Hephsiba Korlapati, a senior official in the city's COVID-19 response team, told Reuters.

In all, India has 906,752 cases of the novel coronavirus with 28,498 new infections reported on Tuesday, according to data from the federal health ministry, the third highest total in the world behind Brazil and the United States.

While cases in the main cities of Mumbai and Delhi account for most of the tally, infections are picking up in smaller cities, forcing authorities to re-impose curbs.

The western city of Pune, which is also an industrial and tech hub, began a 10-day shutdown on Monday while cities as far flung as Shillong in the remote northeast to Srinagar, the main city of Kashmir in the north, imposed new curbs on movements to contain the virus.

The curbs raised questions about prospects for India's growth, Japan's biggest brokerage and investment bank, Nomura, said in a note.

"We also find growing evidence that after the initial normalisation in activity, mobility trends have started to plateau and fall lately," Nomura said.

"This implies that growth could remain below pre-pandemic peaks for a prolonged period of time," they said.