CIUDAD JUAREZ, Mexico, May 10 (Reuters) - Gunmen shot and killed a police chief of this Mexican border city early on Saturday, police said, the sixth high-ranking officer killed in the country in less than a week.

Juan Antonio Roman was shot outside his home as he stepped out of his pickup truck, a spokesman for the local police told Reuters. He was the number two policeman in the city across the border from El Paso, Texas.

President Felipe Calderon is struggling to reduce rampant violence even though he has deployed tens of thousands of soldiers and federal police around the country to bring powerful drug cartels under control.

More than 2,500 people were killed in drug-related violence in Mexico last year. Some 1,100 people have died so far this year as the drug gangs battle each other and security forces.

Hired gunmen believed to be in the pay of the Sinaloa cartel murdered Edgar Millan, one of the country's top federal policemen, at his home on Thursday.

Hours before Millan's funeral on Friday, Esteban Robles, a senior detective in Mexico City, was gunned down in front of his apartment, shot seven times in the head, neck and chest.

Two other senior policemen were shot in the capital in recent days, and drug hit men killed Saul Pena, a top police officer in Ciudad Juarez. (Reporting by Ignacio Alvarado; Editing by Xavier Briand)

AlertNet news is provided by