MEXICO CITY – Mexican soldiers and police have been deployed to track down those behind this week’s murder of the son of a prominent leader of the Institutional Revolutionary Party, or PRI, a crime that rocked the country’s political class.

Jose Eduardo Moreira Rodriguez, 25, son of a former PRI chairman and erstwhile governor of the northern state of Coahuila, Humberto Moreira, was shot and killed near the U.S.-Mexico border.

Authorities are investigating the possibility that organized crime elements were involved or even that the homicide may have been an act of revenge by the violent Los Zetas drug cartel’s second-in-command, Miguel Angel Treviño Morales,

The 25-year-old victim was regional coordinator of social development programs for the violence-wracked state of Coahuila, whose governor, Ruben Moreira, is Moreira Rodriguez’s uncle.

In a brief statement to reporters, Coahuila Attorney General Homero Ramos said few details about the crime are known but that a joint army and police operation had been launched Thursday to seek out those responsible for the murder.

The body was found Wednesday night on a rural road hours after Moreira Rodriguez had concluded a working tour of communities in that state.

Representatives of the navy; the Defense Secretariat, which oversees the army and the air force; and the Public Safety Secretariat, the ministry that supervises the federal police, will take part in the federal and state investigation, Ramos said.

The special team of investigators began working Thursday under the direction of the head of the Federal Police’s Regional Security Division, Luis Cardenas Palomino.

Press reports Thursday said the murder may have been in reprisal for Wednesday’s deaths of five suspected drug-gang enforcers in a clash with an elite Coahuila state police unit.

A day earlier, another four suspected criminals perished in another clash with members of that same police unit. Both confrontations occurred in the city of Piedras Negras, which lies across the border from Eagle Pass, Texas.

Mexican weekly Proceso, meanwhile, said on its online edition that the killing of Moreira Rodriguez could have been revenge for the shooting death of a nephew of notorious Zetas boss Treviño Morales, alias “Z40.”

According to that report, Treviño Morales’ nephew was killed in Wednesday’s clash in Piedras Negras.

A security spokesman in Coahuila refused to comment on that report and told Efe that all the information was being coordinated by the state’s attorney general, who could not be reached by telephone.

“My son was another victim of this war,” a distraught Humberto Moreira told reporters during Thursday’s funeral. “They killed my son. They shot him twice in the head.”

President Felipe Calderon said in a statement that he deeply regretted the “cowardly murder” of Moreira Rodriguez, while President-elect Enrique Peña Nieto, a member of the PRI, condemned the killing and said it “should not go unpunished.”

Humberto Moreira, who served as Coahuila’s governor from 2005 to 2011, became PRI chairman after leaving office.

He resigned on Dec. 2 amid a scandal over allegedly improper contracting during his time as governor of that state.

Moreira’s resignation was prompted by statements made a day earlier by Peña Nieto, who said the controversy over the surge in Coahuila’s public debt had hurt the PRI. EFE