The mayor of a city south of Mexico's capital was shot to death on Saturday, less than a day after taking office, officials said.
Gunmen burst into the house of Mayor Gisela Mota in the city of Temixco and killed her, said the government of Morelos state, where Temixco is located. Two presumed assailants died in the attack and two others were detained, said Morelos Gov. Graco Ramirez in the government statement.
Officials attributed her killing to organized crime.
Mota's leftist Democratic Revolution Party released a statement describing her as "a strong and brave woman who on taking office as mayor, declared that her fight against crime would be frontal and direct."
Temixco is a city of about 100,000 people neighboring Cuernavaca, a resort and industrial city which has been suffering kidnappings and extortion linked to organized crime groups.
Though Cuernavaca is the state capital of Morelos, Temixco is the seat of several state institutions including the Public Security Commission, which coordinates state and local police forces. Morelos also neighbors drug cartel-plagued Guerrero state.
Mota, who had been a federal congresswoman, was sworn into office on New Year's Day. She was killed the following day.
Morelos Gov. Graco Ramírez vowed there "would be no impunity" in her killing and promised that state officials would not cede to the challenge presented by organized crime.
Federal and state forces are deployed in Cuernavaca and municipalities near the Guerrero state border in what is called "Operation Delta."
Local mayors and officials in Mexico have often been targeted by drug cartels.