India's capital region of Delhi ordered a six-day lockdown on Monday as daily Covid-19 cases nationwide hit a new record and the health system crumbled under the weight of new infections.
India's hospitals are struggling with a shortage of beds, oxygen and key medicines as infections pass the 15 million mark, second only to the United States.
"Delhi's health system is unable to take more patients in big numbers," Chief Minister Arvind Kejriwal told a virtual press briefing on Monday.
"If a lockdown isn't implemented now the situation will go beyond control."
British Prime Minister Boris Johnson cancelled a planned trip to India next week due to the coronavirus, his office said.
Fewer than 100 critical care beds were available in the city of New Delhi, with a population of more than 20 million people, Kejriwal had said on Sunday, as social media was flooded with complaints.
Daily Covid-19 cases in India jumped a record 273,810 on Monday. Deaths rose a record 1,619 to 178,769.
Delhi goes into lockdown on Monday night.
It joins around 13 other states across the country that have decided to impose restrictions, curfews or lockdowns in their cities, including India's richest state of Maharashtra and Prime Minister Narendra Modi's home state of Gujarat, where the industrial city of Ahmedabad is also grappling with a shortage of beds.
Criticism has mounted over how Modi's administration has handled India's second wave of the pandemic, with religious festivals and election rallies being attended by thousands.
Leaders including Home Minister Amit Shah are set to hold further road shows and public meetings on Monday.
Hong Kong late on Sunday said the Asian financial hub will suspend flights from India, Pakistan and the Philippines from Tuesday for two weeks.
As of Monday, India had administered nearly 123.9 million vaccine doses, which is the most in the world after the United States and China, though it ranks much lower in per capita vaccination.