MEXICO CITY: Arturo Beltran Leyva, one of Mexico's most wanted men and the head of a top drug cartel has been killed in a military operation south of Mexico City, the Navy said.

"An intense battle between presumed members of Beltran Leyva's criminal cartel organization and members of the Mexican Marine infantry, resulted in the death of Arturo Beltran Leyva tonight," a statement said overnight Wednesday.

Beltran Leyva, 47, was the country's third most wanted man, and a reward of 1.5 million dollars had been offered for information leading to his capture.

As head of one of the most powerful and violent cartels responsible for violence that has ravaged Mexico in recent years, Beltran Leyva's death represents a huge coup for the government of President Felipe Calderon.

The so-called godfather of the "Beltran Leyva brothers" cartel was killed along with three gang members on Wednesday night. A fourth committed suicide after being surrounded by troops.

Three soldiers were injured by grenade fragments during the operation in Cuernavaca, a city of 350,000 that is a popular weekend retreat spot.

The firefight was so intense that many residents had to be evacuated to a nearby sports stadium, local radio reported citing police.

Admiral Jose Luis Vergara, a Navy ministry spokesman, told a local television station that the operation had been planned for months after extensive intelligence work.

The Beltran Leyva brothers cartel was formed after a split with the notorious Sinaloa cartel headed by Joaquin "El Chapo" Guzman, who escaped from a Mexican prison in 2001 and appears in Forbes magazine's world billionaires list.

Arturo Beltran Leyva, nicknamed the "boss of bosses," reportedly worked with the Colombia Norte Del Valle cartel to distribute cocaine and other drugs in the United States.

In August 2008, the US Justice Department unsealed indictments against him and 42 other defendants in connection with drug trafficking.

The indictments claimed they had imported and distributed nearly 200 metric tons of cocaine and large amounts of heroin in the United States and smuggled cash proceeds of up to 5.8 billion dollars through the United States and Canada.

He was also accused of hiring hitmen "who carried out hundreds of acts of violence in Mexico, including murders, kidnappings, tortures and violent collections of drug debts."

Arturo Beltran Leyva's brother, Alfredo, was arrested in January 2008 in the first major capture of a drug cartelleader for the Calderon administration.

The conservative Mexican president has staked his office on tackling the drug cartels whose influence has spread throughout Mexican society, infiltrating the country's police and political system.

Bloody violence between drug gangs, particularly struggles over lucrative drug-smuggling routes into the United States has left the region along Mexico's border with the United States one of the most dangerous in the world.

More than 14,000 people in Mexico are believed to have been killed in violence related to the drug cartels in the past three years alone.