The world's most polluted capital, New Delhi, has closed a major stretch of road to private cars for a few hours, hoping to give its citizens a brief breath of fresh air by observing a car-free day.

Only public transport was allowed to ply Thursday on the road from Old Delhi to the doorstep of Parliament.

The city's top elected official, Arvind Kejriwal, led hundreds of cyclists as they pedaled the route to encourage people to use public transport.

Although the event covered only a six-kilometer (4-mile) stretch, many people hailed the Delhi government's effort as a first step to clean the city's heavily polluted air.

Air pollution kills millions of people every year, including more than 627,000 in India, according to the World Health Organization.