The murders of two aides to Mexico City's Mayor Clara Brugada were meticulously planned by experienced gunmen, prosecutors said.

Mexican authorities have not said whether they see the slayings as targeted. They come after a year of heightened political violence.

Two top aides of Mexico City Mayor Clara Brugada were shot dead after being ambushed by gunmen on a motorbike in a daytime attack in the city center on Tuesday. The victims were the mayor's private secretary,