CULIACAN, Mexico, May 14 (Reuters) - Suspected drug hitmen threw grenades and opened fire on a police station in Mexico's Sinaloa state on Wednesday, just hours after the government sent thousands of troops to fight a powerful drug cartel there.

A group of 10 to 12 heavily armed men shot at the station with machine guns and attacked three other houses, killing one person, in the town of Guamuchil, about an hour away from Sinaloa's capital of Culiacan.

"They fired shots and threw (two) grenades and both of them exploded," a local policeman at the Guamuchil station told Reuters by telephone, asking not to be named.

The six policemen in the station were not injured in the attack in the early hours of the morning.

On Tuesday, President Felipe Calderon sent more than 2,700 troops into the state, known as the home of the country's most wanted man, Joaquin "Shorty" Guzman, head of the Sinaloa drug cartel. Soldiers patrolled Culiacan and a nearby town in military vehicles.

More than 1,100 people have been killed in Mexico this year as drug gangs fight each other and the security forces.

Calderon, a conservative who has sent 25,000 troops and federal police to fight drug cartels across Mexico since late 2006, pledged last week to take back Mexican streets from drug traffickers and gunmen.

But the latest attack shows the difficulty of a frontal attack on the drug cartels in their home territory. (Reporting by Mica Rosenberg; Editing by Cynthia Osterman)

AlertNet news is provided by