Southern Mexico mayor shot dead in her office

Four armed men stormed a mayor's office in southern Mexico, killing her and another member of her staff on Sunday, police said, in the country's latest deadly targeting of a local politician.

The men arrived on motorcycles at the town hall in San Mateo Pinas, in the state of Oaxaca, police said.

After threatening officers guarding the facility, they stormed into Mayor Lilia Garcia's office and proceeded to shoot her and another official, Eli Garcia, dead.

Two municipal police officers were also wounded in the attack, authorities said.

"There can be no impunity for this act," Oaxaca Governor Salomon Jara wrote on social media.

The state prosecutor's office said it was investigating the attack, while military and federal agents were deployed in the area.

Dozens of local officials in Mexico have been targeted by organised crime groups in recent years, especially in areas where powerful drug trafficking gangs operate.

The violence has recently spread to the capital, Mexico City, where two close associates of Mayor Clara Brugada were murdered a month ago in public.

Criminal violence, most of it linked to drug trafficking, has claimed around 480,000 lives in Mexico since 2006, with more than 120,000 people missing.