In the video, the frightened but determined voice of a schoolteacher is heard as she attempts to maintain calm among a group of kindergartners lying on the floor before her, asking them to join her in a singalong as gunfire shatters the air outside.

The teacher refers to the children as "my love," "precious" and "little ones" during the stirring clip filmed last week in the city of Monterrey, in northern Mexico. It's gone viral, igniting once more a public debate over the government's campaign against drug gangs and earning accolades for maestra Martha Rivera Alanis, reports the Associated Press.

The Nuevo Leon state government honored Rivera for "outstanding civic courage" in a ceremony today.

The 33-year-old mother of two said she was frightened, but that her "only thought was to take their minds off that noise." The song she chose during the ordeal is a Spanish-language version of a tune popularized by the children's TV program "Barney and Friends," and makes reference to chocolate droplets falling from the sky.

Rivera filmed the video during a gunfight Friday in which five people were killed at a taxi stand in La Estanzuela, a district in south Monterrey. According to a local news site, Regioblogs, the teacher posted the video to her Facebook account and then was asked permission to have it reproduced on YouTube and linked to the site. So far the original clip has garnered more than 714,000 views.

"We do drills constantly, because the area where we are is a high-risk zone," Rivera said, according to reports. The children, she added, "behaved in the way we had practiced."

Monterrey, a prosperous industrial hub, has seen a wave of drug-related violence as the Gulf and Zeta cartels battle over human- and drug-smuggling routes into the United States. The turf war has led to daylight shootouts on busy streets, attacks on bars and nightclubs, and "narco blockades" that have left residents terrified.

Shortly after the shootout, Rivera posted on Twitter: "It was very bad, my little ones in the kindergarten were very scared, and I was too! ENOUGH OF THIS!"

Other posters on blogs and social-networking sites have pointed to the clip as another example of the drug war's traumatizing effects on ordinary citizens. One man said on Twitter: "Regarding the prize for the teacher, I think that's good, but I am left asking: How many anonymous heroes do we have who are not filmed on video?"

-- Daniel Hernandez in Mexico City

Video: YouTube via Regioblogs