Mexico scored a success in its war on drug cartels, announcing that its security forces killed the boss of the 'La Familia' drug cartel in a shoot-out in the western state of Michoacan.

Nazario Moreno, one of the leaders of the powerful drug trafficking cartel, was gunned down Thursday by police in the town of Apatzingan, government spokesman Alejandro Poire said.

At least three alleged La Familia gunmen, five officers and three civilians were killed in the shoot-out, Poire said, adding that the toll could be higher because many cartel members fled with their wounded and possibly some dead.

"Various sources and information obtained from the operation agree that Nazario Moreno Gonzalez, also known as 'El Chayo' or 'The Doctor,' the main leader and one of the founders of La Familia, was shot dead yesterday," said Poire, the spokesman on security issues.

Moreno, believed to be about 40 years old, is among the country's 24 most-wanted drug cartel leaders, and has a 2.4 million dollar bounty on his head.

Mexican authorities on Tuesday captured La Familia's co-boss Jose Antonio Arcos, one of Mexico's most wanted drug lords. Arcos is also sought in the United States.

Moreno founded La Familia -- The Family in English -- in 2006 along with Jose de Jesus Mendez, also known as 'El Chango,' and Servando Gomez Martinez, 'La Tuta,' both of whom are believe to be alive.

Police and navy marines on Friday rushed to Apatzingan, a town of some 100,000 near the Michoacan state capital Morelia, as military helicopters buzzed the area searching for cartel members.

Clashes between police and La Familia gunmen broke out late Wednesday in Apatzingan, which is also Moreno's home town. Police believe the group's main headquarters were located nearby.

Alleged La Familia supporters, many carrying weapons, set stolen vehicles ablaze at the main points of access to the town.

La Familia, one of the seven main Mexican drug cartels, blends family values and quasi-religious zealotry with brutal enforcement methods. Police say it specializes in the production of synthetic drugs such as methamphetamine.

Moreno, who is also known as 'El Mas Loco' (The Craziest), is the author of "The Gospel of La Familia," a manual distributed to group members that gives paternal advice, warns against the use of drugs and alcohol, and justified crimes of retribution as "divine justice."

Moreno got involved in marihuana trafficking in the 1990s in the northeastern state ofTamaulipas, which borders with Texas, and worked for the powerful Gulf Cartel, saidGabriel Regino, head of the Center of Studies for Security and Justice.

When he returned to Michoacan in 2006 he formed La Familia and hired members ofLos Zetas -- Mexican ex-Special Forces soldiers the Gulf Cartel had hired as enforcers, but had since split with them -- to train his gunmen.

But some of the Zetas decided to stay, and soon La Familia was at war with the ex-soldiers as well as the Gulf Cartel.

La Familia made headlines in October 2005 when members rolled five human heads onto a nightclub dance floor. Along with the heads was a message stating that La Familia did not kill women or children. "Only those who should die will die. Let everyone know, this is divine justice," it read.

Michoacan is the home state of President Felipe Calderon, who launched a nationwide crackdown on the drug cartels after taking office in late 2006. His first target was Michoacan.

La Familia, however, openly challenged the federal government, even hurling grenades at a holiday crowd in Morelia in September 2008 that killed eight people.

In late 2009 it claimed the killings of 16 federal police officers. Twelve of their bodies were found heaped next to an area highway.

Mexican authorities have been battling a spiraling wave of drug-related crime and murder that has killed more than 28,000 people since 2006, despite the deployment of some 50,000 troops across the country.

The FBI arrested more than 300 La Familia members a year ago in the United States.