Two hundred sailors raided an upscale apartment complex and killed one of Mexico's top kingpins in a two-hour gunbattle Wednesday, one of the biggest victories yet in President Felipe Calderon's drug war.

Arturo Beltran Leyva, the "boss of bosses," and three members of his cartel were slain in the shootout in Cuernavaca, just south of Mexico City, according to a navy statement. A fifth cartel member committed suicide during the shootout.

Cartel gunmen hurled grenades that injured three sailors, the navy said. An Associated Press reporter at the scene heard at least 10 explosions.

During the gunbattle, sailors went door to door to move residents of the apartment complex to the gym, according to a woman who said she was speaking by cellphone to her husband inside. She would not give her name out of fear for her safety.

Beltran Levya is the highest-ranking figure taken down under Calderon, who has deployed more than 45,000 troops across Mexico to crush the cartels since taking office in December 2006. The offensive has earned Calderon praise from Washington even as 14,000 people have been killed in a wave of drug-related violence.

The last time Mexican authorities killed a major drug lord was in 2002, when Ramon Arellano Felix of the Tijuana Cartel was shot by a police officer in the Sinaloa resort of Mazatlan.

Beltran Levya was one of five brothers who split from the Sinaloa Cartel several years ago and aligned themselves with Los Zetas, a group of former soldiers hired by the rival Gulf Cartel as hit men. The split is believed to have fuelled much of the bloodshed of recent years.

Key cartel

The U.S. Drug Enforcement Administration says the Beltran Leyva Cartel is key in the importation and distribution of tons of cocaine in the United States, as well as large quantities of heroin. Mexico considers the group one of its six major cartels.

The Mexican government had listed Arturo Beltran Leyva as one its 24 most-wanted drug lords and had offered a $2.1 million US reward for his capture.

Born in the Pacific coast state of Sinaloa, the Beltran Leyva brothers worked side by side with Joaquin (El Chapo) Guzman, the leader of the Sinaloa Cartel, before they broke away after Gulf Cartel leader Osiel Cardenas was arrested in 2003. They soon seized the lucrative drug routes in northeastern Mexico.

U.S. officials say the Beltran Leyva Cartel has carried out heinous killings, including numerous beheadings. The gang also has had great success in buying off public officials, police and others to protect their business and get tips on planned military raids.

The U.S government added Beltran Leyva and his cartel to the Foreign Narcotics Kingpin Designation Act last year, a movement that denied him access to the U.S. financial system.

The state of Morelos, where Cuernavaca is located, and neighbouring Guerrero have seen a spike in violence in recent months, with dozens of people killed. Some of the mutilated bodies have appeared with pieces of paper signed "boss of bosses," Beltran Leyva's nickname.

On Friday, sailors raided a party in the mountain down of Tepotzlan, near Cuernavaca, where they killed three alleged Beltran Leyva Cartel members and detained 11. They also detained Ramon Ayala, a Texas-based norteno singer whose band was playing at the party. Ayala is being held on suspicion of ties to organized crime.