Praxedis G. Guerrero, Mexico: A 20-year-old female college student is the new police chief of one of Mexico's most dangerous drug war towns on the US border, where policemen have quit and officials have been killed.

Marisol Valles, who studies criminology in Mexico's violent city of Ciudad Juarez, took charge of the police force in the neighbouring municipality of Praxedis G. Guerrero near El Paso, Texas, just days before hitmen shot and killed a local official.

The mother of an infant son heads a force of just 13 agents, nine of whom are women, and can count on just one working patrol car, three automatic rifles and a pistol to take on powerful drug cartels waging war over smuggling routes into Texas.

Valles, who is petite, with long brown hair, painted pink nails and black glasses, said she was not cowed by the violence and had not received threats since taking office last week. The town's new mayor said Valles was the best candidate among several who applied for the job.

"The situation can improve if we believe in ourselves and believe there is hope. I want to carry this through and show that we can do this," she told Reuters on Wednesday in Praxedis in Chihuahua, Mexico's most violent state.

"We are doing this for a new generation of people who don't want to be afraid anymore," she added.

Praxedis' former mayor and police chief finished their terms despite threats by drug gangs.

Valles will also oversee policing in the nearby town of El Porvenir, where the top official was killed along with his son in Ciudad Juarez over the weekend. Drug hitmen killed the mayor of the nearby town of Guadalupe Distrito Bravo, which is outside Valles' remit, in June.

Heavily armed men have torched homes, fired on shops and businesses and killed local police in El Porvenir, across the border from the Texas town of Fort Hancock.

The area, known as Juarez Valley, has been sucked into the spiraling violence, rapidly becoming a no man's land where people are abandoning towns despite an army presence.

Drug violence has killed almost 7,000 people in and around Ciudad Juarez since early 2008, while more than 29,000 people have died across Mexico since President Felipe Calderon launched his crackdown on drug cartels in December 2006.

Bloodshed has exploded around Ciudad Juarez as local cartel boss Vicente Carrillo Fuentes fights off an offensive by Mexico's No. 1 fugitive drug lord, Joaquin "Shorty" Guzman.

Calderon has pledged to reform Mexico's police and provide better salaries that are often as low as $300 a month. He wants Congress to approve a plan to put municipal police control in the hands of the country's 32 state governments.