Tlaxiaco Mayor Alejandro Aparicio was on his way to city hall on Tuesday when he was shot.
CNN  — 

The mayor of a town in the Mexican state of Oaxaca was killed less than two hours after taking office, the state attorney general’s office said.

Alejandro Aparicio had just been sworn in as mayor of Tlaxiaco on Tuesday and was on his way to a meeting at city hall along with some of his colleagues when a man opened fired and struck him, the office said.

Aparicio and at least three others were rushed to a hospital, where the mayor was pronounced dead. He died of internal bleeding after suffering a gunshot wound that punctured his right lung, the attorney general’s office said.

Another local official who was injured during the attack died Wednesday morning. Two other people who suffered gunshot wounds were still being treated Wednesday, officials said.

Aparicio had been touring several city offices and was surrounded by supporters when he was shot on the street.

A live video stream on his Facebook page shows dozens of people standing in confusion in the aftermath of the attack, while others held a man they believed was responsible on the ground.

A 34-year-old man, who was only identified as J.M. V., has been arrested in connection with Aparicio’s death, the attorney general’s office said.

The suspect, who is from the nearby state of Chiapas, was previously a police officer in northern Mexico, officials said. Authorities believe he is the only person linked to Aparicio’s death.

Oaxaca Gov. Alejandro Murat condemned the attack and called for a comprehensive investigation into Aparicio’s death.

“I strongly condemn the attack against the Tlaxiaco mayor,” Murat tweeted. “I express my condolences to his family and the people of Tlaxiaco.”

Aparicio was the first member of Mexican President Andrés Manuel López Obrador’s leftist party, Morena, to be elected as mayor in Tlaxiaco.

President López Obrador told reporters during a news conference on Wednesday that he was surprised by the attack, saying Oaxaca is one of the least-violent states in the country.

Aparicio is the second mayor killed in Mexico since President López Obrador took office last month. At least 72 mayors and mayors-elect have been killed since 2006, according to Mexico’s National Association of Mayors.

Tlaxiaco is about 65 miles northwest of the state capital of Oaxaca. It’s also the hometown of Yalitza Aparicio, the star of director Alfonso Cuarón’s “Roma.” It’s unclear whether she is related to the mayor.

CNN’s Clara Lopez and Catherine Shoichet contributed to this report.