The mayor of a city south of Mexico's capital was shot dead less than a day after taking office, officials said.

Gunmen opened fire on Mayor Gisela Mota on Saturday at her house in the city of Temixco, said the government of Morelos state, where Temixco is located.

Two presumed assailants were killed and three others, including a minor, were arrested after a pursuit, said Morelos security commissioner Jesus Alberto Capella. He said the suspects fired on federal police and soldiers from a vehicle.

On his Twitter account, Morelos Governor Graco Ramirez attributed Mota's killing to organised crime, without citing a particular drug cartel or gang.

Cartels seeking to control communities and towns have often targeted local officials and mayors in Mexico.

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."

'No impunity'

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 organised crime groups.

Though Cuernavaca is the 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 neighbours drug cartel-plagued Guerrero state.

Mota, who had been a federal congresswoman in her early thirties, was sworn into office on New Year's Day. She was killed the following day.

Morelos Governor Ramirez vowed there "would be no impunity" in her killing and promised that state officials would not cede to what he described as a "challenge from criminals."

Federal and state forces are deployed in Cuernavaca and municipalities near the Guerrero state border in what is called operation "Delta."

Capella did not provide more details about the attack on Mota, but said that when the suspects were detained, authorities found a 9mm gun, an Uzi, ski masks and an SUV with Mexico State licence plates.

Javier Perez Duron, Morelos attorney general, said that the arrested suspects had been tied to other crimes, but declined to provide more details.