Gunmen block roads in Mexico's drug-plagued north

MONTERREY, Mexico (Reuters) - Armed men likely linked to drug gangs blocked highways with trucks and buses in the northern Mexican city of Monterrey on Friday in an apparent attempt to hamper army operations near the U.S. border.

Gunmen pulled truck and bus drivers out of their vehicles in the wealthy business city and used them to set up blockades on major four-lane highways, sometimes slashing tires to make it harder to tow them away, police and motorists said.

Some similar roadblocks were set up on Thursday.

Monterrey Mayor Fernando Larrazabal suggested drug trafficking cartels were setting up the roadblocks as a way to derail anti-drug operations by security forces.

"The blockades that we are seeing ... could be actions by people linked to organized crime to block avenues and delay federal, state or municipal forces in some operations," he told the Milenio TV network.

Groups of mainly young men wielding pistols and sticks began blocking roads on Thursday afternoon, parking trailers and SUVs across highways, smashing windows and setting some on fire. Police said no one had been hurt in the incidents and they made only two arrests because the gunmen fled after setting up the roadblocks.

"The guys arrested look like gang members," said Luis Carlos Trevino, police chief of Nuevo Leon state, of which Monterrey is the capital. He said they may be directly linked to a drug cartel but gave no details.

Police used tow trucks to unblock all roads by Friday evening, easing traffic jams in the city.

"I saw how a group of men with guns forced a water truck driver out of his vehicle and then turned the truck across the lanes to stop all the traffic," one motorist told local radio, without giving his name.

Drug violence has exploded across Mexico since President Felipe Calderon came to power in late 2006 and set the army on smuggling gangs. Turf wars between rival cartels and security forces have killed nearly 19,000 people in three years, with the worst of the bloodshed seen in northern border cities.

Trevino said there had been 31 road blockades in and around Monterrey, a modern manufacturing city inland from the border but close to Texas, over the past 24 hours.

Considered one of Latin America's premier business cities, Monterrey has been increasingly engulfed by violent crime as battles between rival gangs spill into once tranquil parts of Mexico, alarming Washington, foreign investors and tourists.

U.S. Secretary of State Hillary Clinton and U.S. Secretary of Defense Robert Gates are due in Mexico City on Tuesday to discuss escalating violence with Calderon following the killing of three people linked to the U.S. consulate in Ciudad Juarez, Mexico's most violent drug war city.

Drug killings have surged in recent weeks as the Gulf cartel, which controls most trafficking corridors through Monterrey, split from its former armed wing, the Zetas, in a battle that is escalating violence along the border.

(Additional reporting by Gabriela Lopez in Monterrey and Armando Tovar in Mexico City; Editing by Catherine Bremer)