Drug hitmen kill Mexico state police commander

MONTERREY, Mexico (Reuters) - Suspected drug gang hitmen shot dead a senior police commander in the violent Mexican state of Sinaloa on Wednesday, despite the arrival of hundreds of police reinforcements as killings surge.

Gunmen shot dead Sinaloa's state police commander Salomon Diaz as he drove through a suburb of Culiacan, the state's capital and home to one of the country's main trafficking cartels.

"He was shot in the stomach by gunmen with AK-47s," said a police spokesman who declined to be named.

President Felipe Calderon has sent some 25,000 troops across Mexico to fight drug gangs but it has failed to stop drug murders, which have soared to unprecedented levels with more than 1,700 killed in the first six months of this year.

More than 300 people have died in drug-related violence in Sinaloa state so far this year, including 45 in the past two weeks, as drug gangs fight each other and the army.

The Pacific coast state is home to Mexico's most-wanted kingpin, Joaquin "Shorty" Guzman, who officials say has caused the spike in violence by breaking off an alliance with other local drug lords.

Dozens of federal police began arriving in Culiacan on Wednesday to join thousands of troops in place across Sinaloa.

(Reporting by Robin Emmott; Editing by Kieran Murray)