'Maybe they wanted to intimidate us, but it backfired. They just awakened the people,' said one of the older vigilantes, a straw-hatted man without a gun.

Since then, the upstart self-defense movement has spread to other towns and villages such as Las Mesas and El Pericon. On a recent day, Associated Press journalists saw 200 to 300 masked, armed men patrolling, manning checkpoints and moving around in squad-size contingents. Some had only machetes, but most had old single-shot, bolt-action rifles.

Waving guns, they stop each vehicle, and ask for driver's licenses or voter IDs, which they check against a handwritten list of 'los malos,' or 'the bad guys.' They sometimes search vehicles and frisk the drivers.

The commander of the Las Mesas vigilantes explains their motives. "We are not against those who are distributing drugs. That's a way for them to earn a living. Let anyone who wants to poison themselves with drugs do it. What we are against is them messing with the local people."

The movement so far seems to be well-accepted by local residents fed up with crime that plagued this stretch of mountain highway.

'In less than a month, they have done something that the army and state and federal police haven't been able to do in years," said local resident Lorena Morales Castro, who waited in a line of cars at a checkpoint Friday. "They are our anonymous heroes.'"