India extended Covid vaccinations to teens aged 15-18 on Monday, after officials tightened restrictions in big cities to avoid a repeat of last year's devastating outbreak.

More than 200,000 people around India died in a huge spring virus wave that overwhelmed hospitals and crematoriums.

Health workers have since administered more than 1.4 billion vaccine doses but less than half of India's population is fully inoculated, according to government data.

Hundreds of teenagers patiently queued with their parents on Monday morning outside a school turned into a makeshift medical centre in the capital New Delhi.

"It's really great to have your first vaccine," said 16-year-old Soumadeep, after receiving his first dose of the Indian-made Covaxin.

"It's like a new year gift for the children."

Officials have fretted over the arrival of the Omicron coronavirus variant and a sudden rise in daily infections, with some of India's biggest urban centres imposing fresh restrictions last week.

New Delhi and tech hub Bangalore are under overnight curfews from 10 pm each evening, with bars and restaurants in both cities ordered to operate at half capacity.

Mumbai, India's commercial capital, has barred public gatherings of more than four people from 9pm to 6am and restricted wedding ceremonies to 50 guests.