Thousands of Tijuana residents protesting Mexico’s gasoline price hike marched through the city’s streets at midday Sunday, while later in the day crowds of demonstrators swarmed the city’s main port of entry  across from San Ysidro at El Chaparral, with a smaller group at the secondary port of Otay Mesa.

As they did during protests last week, U.S. authorities for several hours diverted southbound traffic from Interstates 5 and 805 away from the San Ysidro crossing and urged motorists to head to the Otay port. The regular flow of traffic was re-established by 7:40 p.m., according to Caltrans.

In Tijuana, municipal police estimated the total number of demonstrators at close to 15,000.  A larger group of more than 40,000 gathered at the Civic Center in Mexicali, Baja California’s state capital; late in the day, protesters managed to block both entrances and exits to the main state government office building and to a federal office building, the newspaper La Cronica reported.

The protests, which have been largely peaceful, are unprecedented in the region, both in size and tone, longtime observers said. Participants voiced wide-ranging dissatisfaction with Mexico’s political and economic status quo, and demanded change.

Baja California’s demonstrators joined similar groups across Mexico who on Sunday called for President Enrique Peña Nieto’s resignation — and for abolishing the system of political parties they charge has led has led to cronyism, corruption and social injustice.

In Tijuana, they sang Mexico’s national anthem and shouted  “Fuera Peña” — Out with Peña. But the Mexican president was not the sole object of their wrath.

Also targeted was Baja California’s governor, Francisco Vega de Lamadrid. Participants carried signs calling for Vega’s ouster and opposing Baja California’s “Ley del Agua,” a new water law that raised water rates and for the first time has opened the possibility for the private sector to take over traditionally public functions such as distribution of water, and sewage and storm drain services.

By midday, traffic was closed for blocks on some of Tijuana’s major thoroughfares, Agua Caliente Boulevard and Paseo de los Heroes. Groups of demonstrators coming from various directions converged in the heart of the city’s Río Zone at the foot of a giant statue of the Aztec ruler Cuauhtémoc. Protesters included doctors and nurses in uniform, members of a Tijuana bar association, Veracruz-style musicians improvising protest lyrics, and residents of Playas de Tijuana who have been waging a battle against paying tolls on the coastal highway.

“Gasoline was the last straw, but we were already fed up with so many things,” said Tijuana resident Jaime Paramo, 64.

“The government is totally corrupt,” continued Paramo, who holds dual U.S. and Mexican citizenship and works as a bird-keeper at the San Diego Zoo. “What’s important is that we all have the basics —  education, health, food — and the majority don’t have this.”

Many participants said word of the protests was spread through social media by various civic organizations, and said that they were not supporting any political party. “This fills me with joy, seeing so many people participating,” said Fernando Ocegueda Flores, president of Asociación Unidos por los Desaparecidos, whose members are searching relatives who have disappeared.

Protests across Mexico have spread since the country’s Jan. 1 gasoline price hikes of up to 20 percent, as Mexico’s government has moved to end subsidies in an effort to deregulate the country’s energy sector.

On Thursday in Mexicali, some 10,000 demonstrators gathered outside the state capital building to protest both the gasoline price hike and the state water law.

On Friday, Gov. Vega said there would be no reversal to the  “Ley del Agua.” But he announced a 20 percent discount for small users who pay their water bills on time — a move to shield the state’s poorest residents from the price increases.

The governor announced a series of other measures aimed at softening the economic blow on the state’s most vulnerable organizations, and said that altruistic nonprofit groups in Tijuana, Ensenada, Rosarito Beach and Tecate would be not be charged for water use under a certain limit.