Protesting against new Mexican fees and rules placed upon the imports of used cars from the United States, Mexican demonstrators stalled and blocked traffic near at least four heavily crossed entry points along the United States' southern border.

According to Reuters, the Veterans International Bridge between Brownsville, Texas and Matamoros, Mexico remained, due to the demonstrations, closed until Monday evening.

The cargo lanes at the port of entry between Calexico and Mexicali remained closed until about 8 p.m.

The traffic at the Otay Mesa entry point in San Diego was finally clearing at around 7:30 p.m., where crowds of protesters had started to gather in demonstration since around 10:20 a.m. and eventually grew to a throng of several hundred people.

In the end, hundreds of fully loaded trucks were unable to cross in order to make deliveries to Tijuana maquiladora factories or even to stock grocery shelves.

The protests were expected, and the U.S. State Department sent out a message on Sunday that warned U.S. citizens of “significantly delayed crossing times and of the potential closure of many of the points of entry between the United States and Mexico due to multiple protests," U-T San Diego reports.

According to the Associated Press,  Mexico imported more than 640,000 used cars from the U.S. for resale in 2013, while selling about 1 million Mexican-made cars, a number that has remained consistent for about four or five years now.

Alfonso Esquer, the Tijuana spokesman for the Mexican trucking chamber CANACAR, called the situation “a huge problem,” U-T San Diego Reports. He said that about 3,000 southbound trucks cross daily through Otay Mesa, and of this amount, 2,000 are loaded trucks and 1,000 cross the border empty in order to pick up products in Mexico and take them to San Diego.