UPDATE 9:30 p.m. EST — Three people have been arrested in connection with the mayor's murder, authorities in Morelos said.
The newly installed mayor of the Mexican city of Temixco was killed Saturday, according to a tweet from Morelos state Gov. Graco Ramirez.
Gisela Mota formally took office with the new year Friday. Mexico City newspaper EL Universal said she was attacked at her home by four gunmen.
Several mayors were killed last year in Mexico, where armed gangs financed by the drug trade control many local communities.
Temixco, located some 60 miles (100 km) south of Mexico City, has a population of about 100,000.
Mota, a former federal member of Congress, belonged to the leftist Party of the Democratic Revolution.
Officials with the Morelos attorney general's office did not immediately return calls seeking additional information about her death.