The decision was announced the same day by Armando Martínez, the president of the College of the Catholic Lawyers of Mexico, who said that the cathedral will not open again until the government can guarantee the security of the faithful and priests.
During the midday Mass at the cathedral Sunday, a group of members of the leftist Party of the Democratic Revolution (PRD) interrupted the liturgy chanting slogans supporting Andrés Manuel López Obrador, the 2006 presidential candidate who lost by a slim margin to Felipe Calderón. López Obrador contested the results, raising allegations of electoral fraud, and proclaimed himself the "legitimate president" of Mexico.
The protesters also threatened the faithful, the priests and Cardinal Norberto Rivera Carrera, archbishop of Mexico City, who was in Rome on Sunday.
"These are acts of aggression that we should not allow," said Martínez, who said the main concern is for the safety of the faithful present in the cathedral, as well as the cardinal, bishops and priests.
The demonstrators said they were provoked by church bells that chimed for an unusually long time, disrupting a rally in the central Zocolo square at which López Obrador was speaking. The dean of the cathedral, Rubén Ávila, told the newspaper El Universal that the bells rang for the normal time for a Sunday Mass.
In a statement released by Hugo Valdemar Romero, director of communication for the Archdiocese of Mexico, he called the event a "condemnable and cowardly act of terror, unequivocal expression of religious intolerance and of the hatred toward the Catholic Church."