Naked cyclists on a roll for healthy transport in Mexico City

Dozens of naked bikers took to Mexico City's streets Saturday to raise awareness of cycling as a healthy transportation option.

Many people get around by car in this megalopolis of more than 20 million, when a greener option might be in order amid worries about climate change.

Participants in the World Naked Bike Ride turned out with Mexican flair, some in underwear and others just as they came into the world -- plus maybe a bike helmet or colourful wrestler's mask.

Biking has gradually become more popular in traffic-choked Mexico City, which has more than four million cars on its roads daily.

Cycling is more common in the city's central districts, where bike rental services have been popping up.

The government has also tried to encourage bike use by building dedicated lanes, an effort to reduce the number of deadly crashes between cars and bikes.

In mid-May, Mexico City's air pollution levels were so high that schools closed and vehicle use was restricted. That reignited discussions on further encouraging bicycling as a commuting option.

The event in Mexico City is part of a global movement promoting greater use of bicycles in large cities and more sustainable transportation solutions.