Mexico City antismog measure sparks protest by thousands whose old vehicle face Saturday ban

Thousands of people are marching and blocking roads in Mexico City to protest a new anti-pollution measure that would ban them from driving on Saturdays.

New anti-smog rules that went into effect Tuesday ban cars and trucks more than 15 years old from operating on Saturdays.

While Mexico City has long had one-day-a-week driving ban for older cars, the older vehicles were allowed to drive on most Saturdays.

The new measure is particularly hard on vendors who sell fruit and vegetables at the city's street markets. Vendors often use creaky old trucks to haul produce to markets set up on city streets on weekends.

The protesters marched through downtown and also blocked traffic on the main ring road serving the metropolis of 9 million.