Mayor Clara Brugada, who holds the second most powerful political post in Mexico, said her secretary Ximena Guzmán and adviser José Muñoz were killed.

Mexican authorities have not said whether they see the shooting as targeted. It comes after a year of heightened political violence.

The victims were Mayor Clara Brugada's private secretary Ximena Guzman and adviser Jose Muñoz, and the assassinations have sent shock waves through the capital, considered relatively safe.