Thousands of people took part in a march over the weekend in Mexico City organized by the "Yo soy 132" student movement to protest the results of the July 1 presidential election and the likely return to power of the Institutional Revolutionary Party, or PRI.
The protesters - students, union members, political activists and members of grassroots organizations - wanted to show unity in the wake of the victory by the PRI's Enrique Peña Nieto.
Between 25,000 and 30,000 people took to the streets of Mexico City on Sunday, officials said.
The demonstration, which organizers dubbed the "National Megamarch against the Imposition," started at the Los Pinos presidential residence and ended at the Zocalo, Mexico City's main plaza.
The different groups taking part in the march split up at that point.
The Yo soy 132 members gathered in front of the National Palace, the seat of federal executive branch, where they held up signs and chanted slogans against Peña Nieto and the PRI.
Some of the signs referred to allegations of vote-buying and violations of campaign spending limits by Peña Nieto's campaign.
Peña Nieto won Mexico's presidency with 38.21 percent of the vote, while leftist Andres Manuel Lopez Obrador took second place with 31.59 percent, according to the final official results released by the Federal Electoral Institute, or IFE.
The TEPJF electoral court has until Aug. 31 to issue a ruling on the challenge filed by Lopez Obrador's Progressive Movement coalition, either certifying Peña Nieto the winner or calling for a new vote. EFE