Mexican authorities Thursday broke up a plot to assassinate two brothers, both leftist lawmakers, including the former campaign manager of the runner-up in last year's presidential election.
Mariana Benitez, a senior prosecutor, said an unspecified number of people were detained in a Mexico City hotel over plans to kill Senator David Monreal and his brother Ricardo, who managed Andres Manuel Lopez Obrador's campaign.
Authorities seized weapons, communications equipment and a sport-utility vehicle, "which they planned to use for the attacks," Benitez told a news conference. The raid was conducted "without violence."
She said the suspects came from outside Mexico City and they had confessed to the crime. An investigation is under way to find any other suspects.
Ricardo Monreal is the coordinator of the Citizen Movement, a small left-wing party, while his brother David is a senator from the Labor Party.
Lopez Obrador lost the July 2012 election to Enrique Pena Nieto, the candidate of the Institutional Revolutionary Party (PRI) that had ruled Mexico for most of the 20th century.
The leftist candidate charged that the PRI bought votes to secure victory, but electoral authorities threw out his claim.