Protesters denounced Mexican President Enrique Peña Nieto on Sunday for flying to Beijing for an economic conference amid nationwide demonstrations over the disappearance of 43 missing students, saying the Mexican leader is more concerned with business interests than with dealing with the gang violence that has led to Mexico’s biggest crisis in decades.

He earlier criticized protests in the capital, Mexico City, that saw demonstrators set fire to the doors of the National Palace. It was the culmination of protests on Saturday in which thousands of Mexicans took to the streets in response to the missing students.

“It’s unacceptable that someone should try to use this tragedy to justify violence,” Peña Nieto told reporters in Anchorage, Alaska, en route to China for the Asia-Pacific Economic Cooperation summit. “You can’t demand justice while acting with violence.”

But protesters and commentators alike ridiculed Peña Nieto’s condemnation as another presidential crisis began to emerge over the weekend. A Mexican media outlet revealed that the Mexican first lady’s $7 million home was built and is registered under the name of a company linked to a $4 billion high-speed rail contract.

The 15,000-square foot property in Mexico City’s most exclusive neighborhood — the house features marble floors and walls, spas and pools — is owned by Ingeniería Inmobiliaria del Centro, which belongs to Grupo Higa, part of the Chinese-led consortium that was awarded the megaproject, which would link Mexico City with the central city of Querétaro, in the country’s first high-speed rail.

The Mexican government, in an unprecedented move, canceled the contract last week once the president realized the media outlet was investigating the deal, according to Mexican commentators. A government statement released on Thursday said the bidding process will be reopened to give others a chance at the project.

But that move is unlikely to appease Peña Nieto critics, who are increasingly calling on him to resign over his administration’s inept investigation into the case of the missing students.

On Friday, Mexican Attorney General Jesús Murrillo Karam announced during a press conference that three gang members told investigators that they set fire to several missing students in a dump near the southwestern city of Iguala. The 43 students went missing on Sept. 26 after clashing with Iguala police while protesting proposed government educational reforms.

The suspects, according to Murillo, said that local police handed them the students and that gang members then took the students to a nearby landfill, killed them and used fuel and tires to burn their bodies for 14 hours — confessions that may have brought an end to a mystery that has captivated Mexico for more than a month. The students’ parents, however, refuse to accept their children are dead. Claiming that the government has repeatedly lied to them, parents said they would hold out hope until DNA tests on the remains, being conducted in Austria, are completed.

Protesters on Monday, including parents of the missing students, called Murillo’s press conference a farce as they blocked access to Acapulco’s airport in the latest demonstrations against the Peña Nieto administration. Before reaching the airport, protesters clashed with police who attempted to block their path, injuring 11 officers, according to a public security official.

“Nobody goes in, nobody goes out until further instructions,” a masked student at the airport told Agence France-Presse as he blocked the airport entrance with other protesters.

After answering questions for an hour on Friday, Murillo ended the press conference abruptly by saying, “Enough, I’m tired.” That comment has come to further haunt the Peña Nieto administration, as protesters pounced on the catchphrase and used it as a rallying cry during weekend demonstrations.

On Saturday, during marches that led to the Zócalo plaza, protesters were seen carrying signs that read, “If you’re tired, resign,” “I’m tired of being scared” and “We are tired, EPN resign!” in reference to Peña Nieto.

Manuel Martínez, a spokesman for the missing student’s parents, said the “Ya me cansé” rallying cry is a clear sign that their demand for answers is gaining strength.

“Señor Murillo Kram, I, too, am tired,” said filmmaker Natalia Beristain in a YouTube video uploaded with the hashtag #YaMeCansé.

“I’m tired of vanished Mexicans, of the killing of women, of the dead, of the decapitated, of the bodies hanging from bridges, of broken families, of mothers without children, of children without fathers.”

With news services