At least three people, including a police officer and a prison guard, were gunned down over the weekend in the northern Mexican state of Chihuahua, officials said.

Gunmen traveling in at least two vehicles killed a Ciudad Juarez municipal police department lieutenant on Sunday.

The officer, who was identified by the department only by the surname of Maldonado, was driving his SUV down a busy street in Ciudad Juarez, a border city located across the Rio Grande from El Paso, Texas, when the gunmen cut him off and opened fire.

Ciudad Juarez, considered Mexico's murder capital, has been plagued by drug-related violence for years.

The murder rate took off in the gritty border city of 1.5 million people in 2007, when 310 people were killed, then it more than tripled to 1,607 in 2008, according to Chihuahua state Attorney General's Office figures, with the number of killings climbing to 2,754 in 2009.

More than 3,100 people were murdered in the border city last year, making 2010 the worst year since a war between rival drug gangs sent the homicide rate skyrocketing in 2008.

A guard at the Aquiles Serdan prison in Chihuahua city, the state capital, was killed by gunmen on Saturday while he was driving to Ciudad Juarez, the AG's office said.

The unidentified guard was attacked at kilometer 18 of the Chihuahua-Ciudad Juarez highway by gunmen aboard a vehicle, the AG's office said.

A 20-year-old man who was dancing at a club in Chihuahua city died after gunmen doused him with gasoline Saturday night and set him on fire, prosecutors said.

The victim, identified as Javier Diaz Chapa, died at a clinic while being treated for second- and third-degree burns over 90 percent of his body, the AG's office said.

Chihuahua has accounted for nearly 30 percent of the more than 40,000 deaths registered in Mexico since President Felipe Calderon declared war on the country's drug cartels shortly after taking office in December 2006.

The violence is blamed on a war for control of smuggling routes into the United States being waged by the Juarez and Sinaloa cartels with backing from hitmen from local street gangs.