A gunman has shot dead two top aides of the mayor of Mexico City, Clara Brugada.

The mayor’s private secretary, Ximena Guzmán, and Brugada’s adviser, José Muñoz, were killed on their way to work on Tuesday morning local time.

Witnesses said an armed man first opened fire on Guzmán, who had stopped her car by the side of a busy avenue to pick up her colleague, and then on Muñoz, who was about to get into Guzmán’s car for their morning commute.

The gunman is believed to have escaped on a motorbike and have had at least one accomplice. The possible motive for the killing is still unknown but the attack is the latest in a series of murders of local politicians across the country.

Mayor Brugada was visibly upset during a news conference when she recalled how she had “shared dreams and struggles” with her two aides over the years they had worked for her.

She said she would ensure the murders would not go unpunished.

President Claudia Sheinbaum was informed of the shooting during her daily morning news conference by the security minister, Omar García Harfuch, who has himself been a target of an armed ambush in the past.

President Sheinbaum described it as “a deplorable incident” and offered Mayor Brugada, who is from the same party as the president, all the support she may need.

Police seized a motorbike and another vehicle they think was used in the attack, while forensic experts examined Guzmán’s bullet-pierced car.

CCTV footage from a nearby building shows a man carrying a motorcycle helmet in one hand and a gun in another, approach Guzmán’s car from the front.

He fires through the windscreen, then shoots Muñoz, before again firing at Guzmán.

As he runs away, he turns around and fires another shot at Muñoz, who is collapsing on the pavement.

Brugada, 61, was elected mayor of Mexico City in June of last year. The position is considered the second most powerful in the country after that of the president.

While local politicians, especially the mayors of small towns, are often targeted in Mexico, attacks on politicians in the capital are more unusual.

One high-profile exception is the ambush in 2020 of García Harfuch, who was Mexico City’s chief of police at the time.

More than two dozen gunmen opened fire on his car and killed two of his bodyguards and a passer-by in one of the most brazen attacks to have occurred in the city.

García Harfuch was hit three times, but survived and went on to become Mexico’s security minister in October of last year.

He said the Jalisco New Generation Cartel, one of Mexico’s most powerful criminal groups, was behind that incident.

Investigators have not yet said who they think was behind Tuesday’s murder of the two aides, but security experts say the deliberate and precise way the gunman operated indicates that he is a professional hitman.