MEXICO CITY — Looting has broken out at several stores in Mexico on the sidelines of protests against a gasoline price increase as authorities detained dozens of people.

Mexicans have blocked service stations, disrupted highway traffic and held protests since the government increased fuel prices by 20.1 per cent on January 1.

But acts of vandalism and looting erupted on Wednesday, prompting Interior Minister Miguel Angel Osorio Chong to instruct the National Security Commission to support local authorities.

The government of the State of Mexico, which surrounds the capital, said in a statement that 161 people were detained for "various acts of vandalism and thefts at shops" in six municipalities.

The statement said "some groups of people have seized on the situation to commit thefts and acts of vandalism under the pretext of protesting the liberalisation of the price of gasoline."

In Mexico City, around 20 people were detained after some shops were looted, the local government’s secretary general, Patricia Mercado, told Radio Formula.

Some shops closed in the afternoon, though Mercado said "there’s no need for that" as she vowed to police would prevent further vandalism.

Federal police reported around 20 new protests and roadblocks in various parts of the country on Wednesday.

President Enrique Pena Nieto defended the price increase, saying it was necessary due to a rise in global oil prices.

"I understand the irritation and anger among the population in general," he said, arguing that not increasing the prices would have been more painful for the economy.

The government says the increase is a necessary first step before prices go down when it lets the market dictate how much drivers will pay in March as part of a sweeping energy reform. — AFP